{"product_id":"vitamin-d3-5000-iu-k2-mk-7-100mcg","title":"Vitamin D3 5000 IU + K2 MK-7 100mcg | Foundation for Bone, Cardiovascular \u0026 Immune Longevity","description":"\u003ch2\u003eThe 30-Second Answer\u003c\/h2\u003e\n\u003cp\u003eVitamin D3 (cholecalciferol) and Vitamin K2 (menaquinone-7) are the foundational pair almost every serious longevity protocol assumes you already take. D3 controls roughly 200 genes related to immunity, mood, bone density, insulin sensitivity, and cellular repair — but only after \u003ca href=\"\/products\/magnesium-glycinate-400mg-sleep-and-nad-methylation\"\u003emagnesium\u003c\/a\u003e activates it into its hormone form (calcitriol). K2 then directs the calcium D3 mobilizes \u003cem\u003einto bone and teeth\u003c\/em\u003e rather than soft tissue, arteries, and kidneys. Take them together and you get the upside of D3 without the cardiovascular calcification risk of D3-alone supplementation.\u003c\/p\u003e\n\u003cp\u003eThe research backbone: roughly 40% of US adults run below 20 ng\/mL serum 25(OH)D — clinically deficient — and another 40% sit in the 20–30 ng\/mL \"insufficient\" band that the Endocrine Society links to higher all-cause mortality (Holick et al., J Clin Endocrinol Metab 2011;96:1911-1930). K2 deficiency is even more common, since modern diets contain almost no natto, hard cheese, or grass-fed organ meat. The Rotterdam Study (Geleijnse et al., J Nutr 2004;134:3100-3105) followed 4,807 adults for 7–10 years and found those with the highest K2 (menaquinone) intake had 50% lower cardiovascular mortality and 25% lower all-cause mortality. Pair that with D3's mortality-reduction signal across multiple meta-analyses and the combination becomes the highest-evidence \"boring foundation\" supplement on the longevity stack.\u003c\/p\u003e\n\n\u003ch2\u003eWhere This Sits in the Foundational Layer\u003c\/h2\u003e\n\u003cp\u003eTrue Health Protocol treats four supplements as the foundational layer that runs underneath every other protocol: \u003ca href=\"\/products\/magnesium-glycinate-400mg-sleep-and-nad-methylation\"\u003eMagnesium Glycinate 400mg\u003c\/a\u003e, this Vitamin D3+K2, \u003ca href=\"\/products\/glycine-1500mg-glynac-partner-glutathione-sleep-longevity\"\u003eGlycine 1500mg\u003c\/a\u003e, and \u003ca href=\"\/products\/taurine-1000mg-cardiovascular-mitochondrial-longevity\"\u003eTaurine 1000mg\u003c\/a\u003e. None of them produce a \"felt\" stimulant effect. All of them appear in the bloodwork, the bone-density scans, and the all-cause mortality curves of long-running cohort studies. The reason this product sits in that layer rather than in the senolytic, NAD+, or beauty stacks is that the receptors and binding proteins it activates — the vitamin D receptor, matrix Gla protein, osteocalcin — are upstream of nearly every other longevity signal. NMN that you swallow into a body running on 18 ng\/mL serum 25(OH)D is NMN landing in a system whose immune surveillance is impaired and whose calcium handling is dysregulated.\u003c\/p\u003e\n\u003cp\u003ePractically, this means: if you build your stack from the top down (the shiny new compound first, the foundation last), the foundation is almost certainly the layer with the largest dollar-per-life-year return. D3+K2 has the longest, most boring evidence base of anything we sell.\u003c\/p\u003e\n\n\u003ch2\u003eWhy D3 and K2 Are the Foundation Most Stacks Skip\u003c\/h2\u003e\n\u003cp\u003eLongevity supplementation tends to chase the new molecule: NMN this year, urolithin A last year, fisetin the year before. The trap is that the headline compounds work \u003cem\u003ethrough\u003c\/em\u003e systems that already need adequate magnesium, vitamin D, and vitamin K to function. \u003ca href=\"\/products\/pure-nmn-500mg-60-capsules-30-day-supply\"\u003eNMN\u003c\/a\u003e can raise NAD+ all you want — if your serum 25(OH)D is 18 ng\/mL, your immune surveillance is still impaired, your insulin sensitivity is still off, and your bones are still demineralizing.\u003c\/p\u003e\n\u003cp\u003eD3 is technically a hormone precursor, not a vitamin. Sunlight on bare skin synthesizes it; modern indoor life, sunscreen, latitude above 35°, darker skin tones, and age-related skin-synthesis decline (a 70-year-old produces about 25% of the D3 a 20-year-old does from the same sun exposure — MacLaughlin \u0026amp; Holick, J Clin Invest 1985;76:1536-1538) leave most adults below the threshold their genome was tuned for. K2 is the partner because D3 raises blood calcium aggressively — without K2 to activate the matrix Gla protein and osteocalcin, that calcium ends up in arteries and kidney stones rather than bone (Schurgers et al., Blood 2007;109:2823-2831).\u003c\/p\u003e\n\n\u003ch2\u003eWhat the Combination Actually Does\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003e1. Bone density and fracture protection.\u003c\/strong\u003e D3 increases intestinal calcium absorption from ~10–15% to 30–40%. K2 then activates osteocalcin — the protein that pulls that calcium into the hydroxyapatite bone matrix. The Yamaguchi MK-7 trial (Knapen et al., Osteoporos Int 2013;24:2499-2507) showed 180 mcg MK-7 daily for 3 years preserved bone strength and reduced height loss in postmenopausal women — D3 alone didn't replicate the effect. The earlier Theuwissen study (Theuwissen et al., Br J Nutr 2012;108:1652-1657) had already established 90 mcg MK-7 as the threshold dose for shifting osteocalcin from undercarboxylated (cOC) to carboxylated (ucOC) form within 8 weeks. The Cochrane review on calcium plus D3 (Avenell et al., 2014) showed roughly a 16% reduction in hip fracture and 14% reduction in vertebral fracture; adding K2 in observational data appears to compound that effect.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e2. Cardiovascular protection via decalcification.\u003c\/strong\u003e Without K2, calcium pulled into the bloodstream by D3 deposits in arterial walls (coronary artery calcification) and heart valves. K2 activates matrix Gla protein (MGP), the body's only known natural inhibitor of vascular calcification. The Rotterdam follow-up data (Geleijnse 2004) showed K2 intake inversely correlated with arterial stiffness independent of D3 status, and the 3-year Maastricht trial (Knapen et al., Thromb Haemost 2015;113:1135-1144) showed 180 mcg\/day of MK-7 actually \u003cem\u003ereduced\u003c\/em\u003e arterial stiffness measured by carotid-femoral pulse wave velocity in postmenopausal women — one of the few interventions ever shown to reverse, not just slow, vascular aging.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e3. Immune surveillance.\u003c\/strong\u003e Vitamin D receptors are present on virtually every immune cell. The 2020 BMJ meta-analysis of 25 RCTs (Martineau et al., BMJ 2017;356:i6583) found D3 supplementation cut acute respiratory infection risk by 12% overall and 70% in adults who started below 25 nmol\/L. The 2021 follow-up (Jolliffe et al., Lancet Diabetes Endocrinol 2021;9:276-292) confirmed the deficient-population effect across 46 trials and 75,541 participants. The mechanism is upregulation of cathelicidin and beta-defensin antimicrobial peptides plus modulation of T-regulatory cells — both directly linked to inflammaging and senescent cell clearance (Liu et al., Science 2006;311:1770-1773 first showed cathelicidin induction by 1,25(OH)2D in human macrophages).\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e4. Insulin sensitivity and metabolic health.\u003c\/strong\u003e The D2d trial (Pittas et al., NEJM 2019;381:520-530) randomized 2,423 pre-diabetic adults to 4,000 IU D3 vs placebo for 2.5 years; the effect on diabetes progression was significant in those with baseline 25(OH)D below 30 ng\/mL but not above. The receptor is expressed on pancreatic beta cells; restoring sufficiency restores first-phase insulin response (Maestro et al., Cell Biochem Funct 2002;20:227-232 mapped the VDRE in the human insulin gene promoter).\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e5. Mood and cognition.\u003c\/strong\u003e D3 modulates serotonin synthesis via tryptophan hydroxylase-2 in the brain (Patrick \u0026amp; Ames, FASEB J 2014;28:2398-2413). The clearest mood improvement in randomized trials shows up in adults whose baseline 25(OH)D was below 30 ng\/mL — i.e., the deficient half of the US adult population (Vellekkatt \u0026amp; Menon, J Postgrad Med 2019;65:74-80 meta-analyzed 4 RCTs in major depression, 947 patients, and found a small but significant improvement on Hamilton scores at week 8).\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e6. All-cause mortality signal.\u003c\/strong\u003e Multiple meta-analyses (Bjelakovic et al., Cochrane 2014; Chowdhury et al., BMJ 2014;348:g1903) link adequate serum 25(OH)D — roughly 40–60 ng\/mL — to lower all-cause mortality, with the pooled estimate from Chowdhury landing at a hazard ratio of 0.86 for the highest vs lowest quartile across 73 cohort studies and 849,412 individuals. The shape is U-curve: too low and too high both increase risk. The combination with K2 widens the safe upper band by directing the extra calcium where it belongs.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e7. Periodontal and dental health.\u003c\/strong\u003e Osteocalcin is also expressed by osteoblasts in alveolar bone; matrix Gla protein protects against soft-tissue calcification in periodontal ligament. Observational data (Adegboye et al., J Clin Periodontol 2010;37:711-717) link low D3 to faster alveolar bone loss; clinical trials of K2 (MK-7) in dental cohorts are smaller but consistent with the bone-mineralization mechanism.\u003c\/p\u003e\n\n\u003ch2\u003eHow D3, K2, and Magnesium Form a Three-Cofactor Loop\u003c\/h2\u003e\n\u003cp\u003eD3 is biologically inert as swallowed. The liver hydroxylates it once to 25(OH)D — the form measured on a blood test — and the kidney hydroxylates it again to 1,25(OH)₂D, the active hormone calcitriol. Both hydroxylation steps require \u003ca href=\"\/products\/magnesium-glycinate-400mg-sleep-and-nad-methylation\"\u003emagnesium\u003c\/a\u003e as a cofactor for the relevant CYP450 enzymes (Uwitonze \u0026amp; Razzaque, J Am Osteopath Assoc 2018;118:181-189). This is the single most common reason adults take D3 for months and don't see their serum 25(OH)D move: they're magnesium-depleted, the activation enzymes can't do their job, and the swallowed cholecalciferol piles up unused.\u003c\/p\u003e\n\u003cp\u003eOnce D3 is activated, calcitriol drives intestinal calcium absorption. Without K2, that calcium reaches the bloodstream but doesn't reach the bone matrix — osteocalcin (the calcium-binding protein in bone) is synthesized in an undercarboxylated form that can't bind calcium until K2 finishes the gamma-carboxylation reaction (Schurgers 2007). The same K2-dependent reaction activates matrix Gla protein in arterial walls, which is what prevents the calcium from depositing in the wrong place.\u003c\/p\u003e\n\u003cp\u003eThis is why the foundational triad — Magnesium → D3 → K2 — has to be taken together to work. Each one fails without the other two. The standard \"D3 alone\" or \"calcium + D3\" supplements that flooded the 2000s are part of why the cardiovascular calcification literature became concerning: D3 was raising serum calcium without the magnesium to activate it cleanly or the K2 to direct it.\u003c\/p\u003e\n\n\u003ch2\u003eHow This Sits in the Longevity Stack\u003c\/h2\u003e\n\u003cp\u003eD3+K2 is not a \"feel something\" supplement. It's foundational chemistry — like Magnesium Glycinate, it runs underneath every other compound rather than acting on its own discrete pathway. If you're on NMN\/NAD+ stacks, fisetin\/quercetin senolytics, or a serious protocol like the Cellular Longevity stack, D3+K2 is the layer that lets the rest of the stack work in a body whose immune surveillance, bone metabolism, and arterial health are intact.\u003c\/p\u003e\n\u003cp\u003eK2 (MK-7) circulates with a half-life of ~72 hours (versus K1's ~1 hour, and MK-4's ~1 hour) — Schurgers et al., Blood 2007 mapped the pharmacokinetics directly — which is why the once-daily dose works. D3's serum half-life as 25(OH)D is even longer at 2–3 weeks, which is why missing a day or two means almost nothing and why blood tests reflect average intake over the prior month rather than yesterday's dose.\u003c\/p\u003e\n\n\u003ch2\u003eWhat's in Each Capsule\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eVitamin D3 (Cholecalciferol)\u003c\/strong\u003e — 5,000 IU (125 mcg). The form your body actually makes from sunlight, not the plant-derived D2 (ergocalciferol) which raises serum 25(OH)D less efficiently per the Tripkovic meta-analysis (Am J Clin Nutr 2012;95:1357-1364, D3 raises 25(OH)D roughly 1.7x more per IU than D2). Sourced from lanolin (the standard high-purity source).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVitamin K2 (Menaquinone-7, MK-7)\u003c\/strong\u003e — 100 mcg. The long-half-life form fermented from natto-derived \u003cem\u003eBacillus subtilis natto\u003c\/em\u003e. MK-7 is the form with the strongest cardiovascular evidence; MK-4 (the synthetic short-half-life form used in some formulations) requires multiple daily doses to maintain serum levels.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMCT oil base (organic coconut)\u003c\/strong\u003e — both vitamins are fat-soluble; the MCT carrier ensures absorption regardless of meal timing. Without a fat carrier, D3 absorption can drop 30–50% (Dawson-Hughes et al., J Bone Miner Res 2013;28:1778-1783).\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eNo magnesium stearate, no titanium dioxide, no synthetic colorants. Vegetable cellulose softgel.\u003c\/p\u003e\n\n\u003ch2\u003eDaily Protocol\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eDefault foundational dose:\u003c\/strong\u003e 1 softgel daily, with the largest fat-containing meal of the day (typically lunch or dinner). Both D3 and K2 are fat-soluble — taking them on an empty stomach or with a low-fat meal can cut absorption by 30–50%.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIf your last 25(OH)D test came back below 20 ng\/mL (clinical deficiency):\u003c\/strong\u003e 2 softgels daily for the first 8–12 weeks, then retest and drop to 1. Going from 18 to 50 ng\/mL takes most adults 2–4 months at 5,000 IU\/day; severely deficient adults sometimes need 10,000 IU\/day under physician supervision for 4–8 weeks before maintenance.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIf you live above latitude 40° (most of Canada, northern US, northern Europe):\u003c\/strong\u003e The same 1-softgel default October through April; you can drop to a softgel every other day May through September if you're getting regular bare-skin sun. Or just keep the daily dose year-round — at 5,000 IU\/day the safety margin is wide and the simplicity is worth it.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIf your BMI is over 30:\u003c\/strong\u003e Adipose tissue sequesters fat-soluble D3, meaning a given oral dose produces a smaller serum 25(OH)D rise. Drisko et al., Am J Clin Nutr 2007 documented that obese adults need approximately 2–3x the oral dose of lean adults to reach the same serum 25(OH)D. Start at 2 softgels\/day, retest at 12 weeks, adjust accordingly.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eStack pairing:\u003c\/strong\u003e Take with \u003ca href=\"\/products\/magnesium-glycinate-400mg-sleep-and-nad-methylation\"\u003eMagnesium Glycinate\u003c\/a\u003e — D3 activation in the kidney is magnesium-dependent (Uwitonze \u0026amp; Razzaque 2018), and inadequate magnesium is the most common cause of \"I'm taking D3 but my levels aren't moving.\" For serious longevity protocols, this trio (Mg + D3 + K2) is the foundation everything else sits on.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eGet tested:\u003c\/strong\u003e A serum 25(OH)D test ($30–50 from most labs, often $0 with insurance) tells you whether your dose is working. Aim for 40–60 ng\/mL year-round; below 30 means more dose, above 80 means less. K2 status is harder to measure directly — undercarboxylated osteocalcin (ucOC) is the gold standard but rarely run by general practitioners.\u003c\/p\u003e\n\n\u003ch2\u003eStack Pairings\u003c\/h2\u003e\n\u003cp\u003eD3+K2 is the connective layer for most of our other stacks. The pairings that change behavior the most:\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eD3+K2 ↔ \u003ca href=\"\/products\/magnesium-glycinate-400mg-sleep-and-nad-methylation\"\u003eMagnesium Glycinate 400mg\u003c\/a\u003e.\u003c\/strong\u003e The activation cofactor. If you only buy one pairing, this is it. Magnesium runs the CYP27A1 (liver) and CYP27B1 (kidney) hydroxylation steps that turn cholecalciferol into 25(OH)D and then calcitriol. Magnesium-depleted adults can take D3 for a year and not move their serum levels.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eD3+K2 ↔ \u003ca href=\"\/products\/calcium-alpha-ketoglutarate-1000mg-caakg-epigenetic-longevity\"\u003eCalcium AKG\u003c\/a\u003e.\u003c\/strong\u003e CaAKG provides calcium to a body whose absorption D3 has just multiplied 2–3x and whose K2 is now directing into bone. The combination is also the standard \"epigenetic longevity\" pairing in the Asadi Shahmirzadi 2020 mouse data.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eD3+K2 ↔ \u003ca href=\"\/products\/omega-3-fish-oil-2000mg-epa-dha\"\u003eOmega-3 EPA\/DHA 2000mg\u003c\/a\u003e.\u003c\/strong\u003e Both are fat-soluble; both share the lipoprotein transport into cell membranes; both modulate inflammaging. The VITAL trial (Manson et al., NEJM 2019;380:33-44) tested D3 and omega-3 in factorial design across 25,871 adults and found additive cardiovascular signals where neither alone reached significance.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eD3+K2 ↔ \u003ca href=\"\/products\/glycine-1500mg-glynac-partner-glutathione-sleep-longevity\"\u003eGlycine 1500mg\u003c\/a\u003e + \u003ca href=\"\/products\/taurine-1000mg-cardiovascular-mitochondrial-longevity\"\u003eTaurine 1000mg\u003c\/a\u003e.\u003c\/strong\u003e Completes the four-pillar foundational layer. Taurine handles cardiovascular ion handling and bile conjugation; glycine handles glutathione and sleep architecture; D3+K2 handles bone, immunity, and arterial decalcification; magnesium handles activation. Together they're the four boring SKUs your future self thanks you for.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eD3+K2 ↔ \u003ca href=\"\/products\/curcumin-1000mg-bioperine-anti-inflammatory-longevity\"\u003eCurcumin 1000mg + BioPerine\u003c\/a\u003e.\u003c\/strong\u003e D3 modulates Th17\/Treg balance from above; curcumin damps NF-κB from below. The combination shows up in autoimmune and inflammatory-aging cohorts with stronger CRP-reduction signals than either alone.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eD3+K2 ↔ \u003ca href=\"\/products\/pure-nmn-500mg-60-capsules-30-day-supply\"\u003eNMN 500mg\u003c\/a\u003e \/ \u003ca href=\"\/products\/rb-nicotinamide-nucleotide-nad-hard-capsules-cellular-energy-anti-aging\"\u003eNAD+ Hard Capsules\u003c\/a\u003e.\u003c\/strong\u003e NAD+ supports the SIRT1 deacetylase that gates VDR signaling. Vitamin-D-sufficient cells respond to calcitriol more effectively when SIRT1 is well-fueled — the two mechanisms aren't redundant; they're sequential.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eD3+K2 ↔ \u003ca href=\"\/products\/quercetin-500mg-senolytic-flavonoid-natural-antihistamine\"\u003eQuercetin 500mg\u003c\/a\u003e + \u003ca href=\"\/products\/fisetin-500mg-senolytic-flavonoid-for-cellular-cleanup\"\u003eFisetin 500mg\u003c\/a\u003e.\u003c\/strong\u003e Senolytics clear senescent immune cells; D3 then re-tunes the surveillance system left behind. Standard \"D+K with a quarterly senolytic pulse\" protocol.\u003c\/p\u003e\n\n\u003ch2\u003eExpectation Timeline\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eWeek 1–2.\u003c\/strong\u003e Nothing felt. Serum 25(OH)D barely moves — this is normal. The half-life means it takes weeks of consistent dosing to shift the average. Don't quit because nothing happened in seven days.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWeek 4–6.\u003c\/strong\u003e First pharmacological effects show up in K2 markers (undercarboxylated osteocalcin and undercarboxylated MGP both decline within 4–8 weeks at 100 mcg MK-7\/day per Theuwissen 2012). If your baseline 25(OH)D was deficient and you're tracking mood or seasonal-affect symptoms, week 4–6 is when the first signal usually appears in the trial data (Vellekkatt 2019).\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWeek 8–12.\u003c\/strong\u003e Serum 25(OH)D reaches new steady-state at the dose. Time for a second blood draw to see where you've landed. Most adults at 5,000 IU\/day move from a baseline 22–28 ng\/mL into the 45–55 ng\/mL target band.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eMonth 3–6.\u003c\/strong\u003e Bone-turnover markers (CTX, P1NP) shift; immune function endpoints emerge in the trial data (Martineau 2017 cumulative risk reduction grows with duration).\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eYear 1–3+.\u003c\/strong\u003e The actual longevity payoff. Bone density preservation (Knapen 2013), arterial stiffness reduction (Knapen 2015), fracture-rate reduction in pooled D-and-K cohorts (Avenell 2014). This is a slow, boring, durable supplement. The biggest mistake is stopping after week 6 because nothing felt different.\u003c\/p\u003e\n\n\u003ch2\u003eWho Should Talk to a Physician First\u003c\/h2\u003e\n\u003cp\u003eD3+K2 is one of the safest supplement combinations on the market, but several conditions warrant professional guidance:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarfarin \/ Coumadin users.\u003c\/strong\u003e K2 directly antagonizes warfarin's anticoagulant effect (Schurgers et al., Blood 2007). Do not start K2 without coordinating with your prescriber to adjust your INR monitoring. Newer anticoagulants (rivaroxaban, apixaban, dabigatran) do not work via the K-cycle and don't have this interaction, but flag it anyway.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHypercalcemia, hyperparathyroidism, or sarcoidosis.\u003c\/strong\u003e These conditions impair calcium regulation; supplemental D3 can push serum calcium dangerously high. Sarcoidosis in particular activates 1-alpha-hydroxylase outside the kidney and can produce calcitriol-driven hypercalcemia at otherwise modest D3 doses.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eActive kidney stone disease.\u003c\/strong\u003e Discuss dose with your nephrologist. The combination with K2 is theoretically protective (K2 should reduce calcium oxalate deposition) but real-world dosing in active stone-formers should be supervised.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePregnancy and breastfeeding.\u003c\/strong\u003e Standard prenatal vitamins typically contain D3 — adding 5,000 IU on top requires obstetrician approval. The pregnancy literature (Hollis et al., J Bone Miner Res 2011;26:2341-2357) supports 4,000 IU\/day as safe and sufficient, but obstetric oversight is the right path.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eChildren under 18.\u003c\/strong\u003e Pediatric dosing is weight-based and should come from a pediatrician.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWilliams syndrome and idiopathic infantile hypercalcemia.\u003c\/strong\u003e Genetic D3 hypersensitivity — explicit contraindication.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRecent fish or soy allergy.\u003c\/strong\u003e Our MK-7 is fermented from \u003cem\u003eBacillus subtilis\u003c\/em\u003e on a soy substrate (the natto base); residual soy is below detection in COA but trace exposure is theoretically possible.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eRoutine drug interactions to flag with your pharmacist: corticosteroids and weight-loss drugs (orlistat) reduce D3 absorption; thiazide diuretics combined with high-dose D3 can raise calcium; phenytoin, carbamazepine, and rifampin accelerate D3 breakdown via CYP3A4 induction; digoxin tolerance narrows as serum calcium rises.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eWhy 5,000 IU? Isn't that high?\u003c\/strong\u003e 5,000 IU is the dose that moves serum 25(OH)D from \"insufficient\" (20–30 ng\/mL) into the longevity-research target band (40–60 ng\/mL) for most adults. The official RDA of 600–800 IU was set in 2010 to prevent rickets, not optimize all-cause mortality. The Endocrine Society's 2011 clinical practice guideline (Holick) lists 1,500–2,000 IU\/day as the floor for adults to maintain sufficiency, and the Institute of Medicine sets 4,000 IU\/day as the Tolerable Upper Intake Level — meaning the dose at which the IOM's expert panel found no signal of harm in the available literature. Doses up to 10,000 IU\/day are within the established safe upper limit cited by the Endocrine Society for healthy adults. If you're sun-exposed, light-skinned, and live south of latitude 35°, you may only need 2,000 IU — half a softgel every other day works for that case.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhy MK-7 instead of MK-4 K2?\u003c\/strong\u003e MK-7 has a serum half-life of ~72 hours; MK-4 is closer to 1 hour (Schurgers 2007). That means MK-7 at 100 mcg\/day maintains stable activation of matrix Gla protein and osteocalcin around the clock, while MK-4 requires 3 doses per day at 15 mg each (a 450x higher daily mass) to do the same job. Every long-term cardiovascular and bone outcome trial that successfully shifted endpoints (Knapen 2013, Knapen 2015) used MK-7 for this reason. MK-4 has a niche use case in osteoporosis Japanese-protocol pharmacology at 45 mg\/day, but for general longevity supplementation MK-7 is the dominant form.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I just get this from sun and food?\u003c\/strong\u003e Mathematically possible, practically not. To synthesize 5,000 IU of D3 from sun, a light-skinned adult needs about 15–20 minutes of midday summer sun on bare arms, legs, and torso — which most modern adults don't get without sunburn risk, and which is impossible above latitude 35° in winter (the UVB wavelengths needed for D3 synthesis don't penetrate the atmosphere at low solar angles). K2 is even harder: 100 mcg of K2 requires either ~50g of natto (most Westerners won't eat it daily), ~200g of hard aged cheese, or ~150g of grass-fed liver. The supplement exists because the diet that produced these compounds in our ancestors no longer exists.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow does this differ from a multivitamin?\u003c\/strong\u003e Most multivitamins contain 400–1,000 IU of D3 (below the threshold to move serum levels) and either no K2 or 50 mcg of MK-4 (the short-half-life form). They're formulated to prevent deficiency disease, not to support the 40–60 ng\/mL target the longevity research uses. A multivitamin is not a substitute for dedicated D3+K2 dosing.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill I feel something?\u003c\/strong\u003e Probably not in week one. The compounds work on slow-turnover systems — bone remodeling cycles run about 3 months, immune adaptation takes weeks, mood effects show up by week 4–6 if your baseline was deficient. The honest answer is: D3+K2 is insurance, not stimulant. The signal it produces is \"fewer winter colds, better lab values, fewer fractures over decades\" — not \"I felt great Tuesday.\"\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDrug interactions to watch?\u003c\/strong\u003e Warfarin (K2 antagonizes it), corticosteroids and orlistat (reduce D3 absorption), thiazide diuretics (raise calcium synergistically), phenytoin\/carbamazepine\/rifampin (accelerate D3 metabolism via CYP3A4 — may need higher doses), digoxin (rising calcium narrows the cardiac glycoside therapeutic window). If you take any prescription medication, run this past your pharmacist before starting.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eShould I take both softgels at once or split them?\u003c\/strong\u003e One per day is fine. Both D3 (half-life as 25(OH)D ~3 weeks) and MK-7 (half-life ~72 hours) have long enough kinetics that splitting the dose adds nothing. Some people prefer the morning fat-meal route because they remember it; others prefer dinner because dinner usually has the most fat. Pick one and be consistent.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I take this on an empty stomach?\u003c\/strong\u003e You can, but you'll absorb 30–50% less (Dawson-Hughes 2013). Take it with the meal of the day that has the most fat — even a tablespoon of olive oil, butter, or avocado is enough to switch on the lipoprotein-mediated absorption pathway.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eVegan considerations?\u003c\/strong\u003e The cholecalciferol in this product is sourced from lanolin (sheep wool grease), which is animal-derived but cruelty-free and the standard high-purity D3 source. Vegan D3 from lichen exists but at higher cost and lower batch consistency. The MK-7 is fermented from \u003cem\u003eBacillus subtilis\u003c\/em\u003e on a plant substrate and is vegan-compatible. The softgel is vegetable cellulose. So this product is vegetarian; the D3 itself is the only step that won't satisfy strict vegans.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat 25(OH)D level should I aim for?\u003c\/strong\u003e 40–60 ng\/mL year-round (100–150 nmol\/L if your lab uses SI units). Below 30 means more dose; above 80 means less; above 100 starts to enter the U-curve right tail and is rarely needed. The Endocrine Society's clinical practice guideline names 30–100 ng\/mL as the sufficient range; the longevity-cohort literature (Chowdhury 2014, Garland 2014) tends to identify 40–60 ng\/mL as the band with the lowest pooled hazard ratios.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhy does my 25(OH)D not move on D3 alone?\u003c\/strong\u003e The single most common reason is magnesium deficiency. CYP27A1 (liver, 25-hydroxylation) and CYP27B1 (kidney, 1-alpha-hydroxylation) both require magnesium as a cofactor (Uwitonze \u0026amp; Razzaque 2018). Adding 400 mg\/day of \u003ca href=\"\/products\/magnesium-glycinate-400mg-sleep-and-nad-methylation\"\u003emagnesium glycinate\u003c\/a\u003e to a stalled D3 protocol very often unsticks the serum levels within 6–8 weeks. Other reasons: BMI over 30 (sequestered into adipose), CYP3A4 inducer drugs, malabsorption (celiac, Crohn's, post-bariatric), liver or kidney disease.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs there a CYP24A1 issue I should know about?\u003c\/strong\u003e About 1 in 33,000 adults carry loss-of-function variants in CYP24A1, the enzyme that catabolizes calcitriol. They develop hypercalcemia at otherwise modest D3 doses. Family history of unexplained kidney stones in childhood, or persistent hypercalcemia despite normal PTH, is the clinical clue. If that history matches, a 24-hour urine calcium and a CYP24A1 sequencing test from your endocrinologist clarifies things.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan K2 reverse existing arterial calcification?\u003c\/strong\u003e The Knapen 2015 trial showed reduction in pulse wave velocity (a functional measure of arterial stiffness) at 3 years of 180 mcg MK-7\/day; whether it actually \u003cem\u003eremoves\u003c\/em\u003e existing coronary calcium scoring deposits is still an open question. The mechanism (matrix Gla protein activation) is consistent with both prevention and partial reversal. Don't expect a CAC score of 400 to drop to zero, but the trajectory of further calcification clearly slows.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs more better? What about 10,000 IU?\u003c\/strong\u003e 10,000 IU\/day is within the Endocrine Society's safe upper limit for healthy adults and is sometimes used in deficient subjects under physician supervision for 4–8 weeks. For long-term maintenance in someone whose 25(OH)D is already at 50 ng\/mL, 10,000 IU is unnecessary and pushes you toward the U-curve right tail. The principle: dose for the lab number, not for the IU count.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eSunscreen and D3?\u003c\/strong\u003e SPF 15+ blocks 99% of UVB. If you wear sunscreen daily on exposed skin, treat your skin synthesis as zero and dose as if you live in a D3-free environment. The skin-cancer protection from sunscreen is real and worth keeping; the D3 supplement just covers the synthesis you sacrifice.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhy is my doctor only ordering 25(OH)D once and never again?\u003c\/strong\u003e Most general-practice protocols treat 25(OH)D as a one-time deficiency screen rather than an ongoing optimization target. If you want to dial in your dose, ask explicitly for an annual or semi-annual 25(OH)D as part of routine bloodwork. Many concierge practices, longevity clinics, and direct-to-consumer labs (Quest, LabCorp, Marek Health) order it without a prescription.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat about K2 and pregnancy?\u003c\/strong\u003e K2 is generally considered safe in pregnancy at supplemental doses; the fetal need for K-cycle activity (bone development, vascular patterning) is real. But \"generally safe\" plus pregnancy plus a longevity supplement equals \"ask your obstetrician first.\"\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes this product contain calcium?\u003c\/strong\u003e No. D3+K2 is the activation and direction system; the calcium itself comes from diet (dairy, leafy greens, sardines with bones, almonds) or a separate supplement like \u003ca href=\"\/products\/calcium-alpha-ketoglutarate-1000mg-caakg-epigenetic-longevity\"\u003eCaAKG\u003c\/a\u003e. Most adults eating a modest dairy-inclusive diet hit 800–1,000 mg\/day of calcium without supplementing.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs the dropper \/ softgel format better than a tablet?\u003c\/strong\u003e Yes for a fat-soluble vitamin. The MCT-oil softgel format means the active is already dissolved in its carrier; absorption is fast and consistent. Compressed tablets of D3 require disintegration and dispersion in the gut and show more inter-individual absorption variability.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I take D3+K2 if I'm on statins?\u003c\/strong\u003e Yes, no direct interaction. The mevalonate pathway statins inhibit is upstream of cholesterol synthesis but doesn't intersect with the D3 or K2 cycles directly. Some observational data suggests statin users have slightly lower 25(OH)D, possibly because both compounds share LDL-particle transport — splitting them by a meal is a small optimization.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat's the difference between cholecalciferol and calcitriol prescriptions?\u003c\/strong\u003e Calcitriol (Rocaltrol) is the already-activated 1,25(OH)2D hormone, prescribed for renal patients whose kidneys can't run the final hydroxylation step. It bypasses both magnesium-dependent activation steps, has a much shorter half-life, and is dosed in micrograms rather than thousands of IU. It's not interchangeable with cholecalciferol and shouldn't be used as a longevity supplement — too narrow a therapeutic window.\u003c\/p\u003e\n\n\u003ch2\u003eThe Science (Selected References)\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eHolick MF, et al. Evaluation, treatment, and prevention of vitamin D deficiency: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab 2011;96:1911-1930.\u003c\/li\u003e\n\u003cli\u003eGeleijnse JM, et al. Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study. J Nutr 2004;134:3100-3105.\u003c\/li\u003e\n\u003cli\u003eKnapen MHJ, et al. Three-year low-dose menaquinone-7 supplementation helps decrease bone loss in healthy postmenopausal women. Osteoporos Int 2013;24:2499-2507.\u003c\/li\u003e\n\u003cli\u003eKnapen MHJ, et al. Menaquinone-7 supplementation improves arterial stiffness in healthy postmenopausal women. Thromb Haemost 2015;113:1135-1144.\u003c\/li\u003e\n\u003cli\u003eTheuwissen E, et al. Low-dose menaquinone-7 supplementation improved extra-hepatic vitamin K status in healthy adults. Br J Nutr 2012;108:1652-1657.\u003c\/li\u003e\n\u003cli\u003eSchurgers LJ, et al. Vitamin K-containing dietary supplements: comparison of synthetic vitamin K1 and natto-derived menaquinone-7. Blood 2007;109:2823-2831.\u003c\/li\u003e\n\u003cli\u003eMartineau AR, et al. Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data. BMJ 2017;356:i6583.\u003c\/li\u003e\n\u003cli\u003eJolliffe DA, et al. Vitamin D supplementation to prevent acute respiratory infections: a systematic review and meta-analysis of aggregate data from randomised controlled trials. Lancet Diabetes Endocrinol 2021;9:276-292.\u003c\/li\u003e\n\u003cli\u003ePittas AG, et al. Vitamin D supplementation and prevention of type 2 diabetes (D2d). NEJM 2019;381:520-530.\u003c\/li\u003e\n\u003cli\u003eManson JE, et al. Vitamin D supplements and prevention of cancer and cardiovascular disease (VITAL). NEJM 2019;380:33-44.\u003c\/li\u003e\n\u003cli\u003eChowdhury R, et al. Vitamin D and risk of cause specific death: systematic review and meta-analysis of observational cohort and randomised intervention studies. BMJ 2014;348:g1903.\u003c\/li\u003e\n\u003cli\u003eBjelakovic G, et al. Vitamin D supplementation for prevention of mortality in adults. Cochrane Database Syst Rev 2014;1:CD007470.\u003c\/li\u003e\n\u003cli\u003eTripkovic L, et al. Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: a systematic review and meta-analysis. Am J Clin Nutr 2012;95:1357-1364.\u003c\/li\u003e\n\u003cli\u003eUwitonze AM, Razzaque MS. Role of magnesium in vitamin D activation and function. J Am Osteopath Assoc 2018;118:181-189.\u003c\/li\u003e\n\u003cli\u003eLiu PT, et al. Toll-like receptor triggering of a vitamin D-mediated human antimicrobial response. Science 2006;311:1770-1773.\u003c\/li\u003e\n\u003cli\u003ePatrick RP, Ames BN. Vitamin D hormone regulates serotonin synthesis. Part 1: relevance for autism. FASEB J 2014;28:2398-2413.\u003c\/li\u003e\n\u003cli\u003eMacLaughlin J, Holick MF. Aging decreases the capacity of human skin to produce vitamin D3. J Clin Invest 1985;76:1536-1538.\u003c\/li\u003e\n\u003cli\u003eAvenell A, et al. Vitamin D and vitamin D analogues for preventing fractures in post-menopausal women and older men. Cochrane Database Syst Rev 2014;4:CD000227.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003eThese statements describe the published research on vitamin D3 and vitamin K2 (MK-7) the molecules and have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Consult a qualified healthcare practitioner before starting any supplementation, especially if you have a medical condition, take prescription medication (particularly anticoagulants), are pregnant or breastfeeding, or are under 18.\u003c\/em\u003e\u003c\/p\u003e\n\n\u003ch2\u003eQuality Notes\u003c\/h2\u003e\n\u003cp\u003eManufactured in cGMP-certified facilities, third-party tested for vitamin potency, heavy metals (lead, arsenic, cadmium, mercury), and microbial contamination. Each batch comes with a Certificate of Analysis verifying both D3 IU content and K2 (MK-7) microgram content. Soy-free in the finished MK-7 step (residual below detection limit), gluten-free, GMO-free.\u003c\/p\u003e\n","brand":"True Health Protocol","offers":[{"title":"Default Title","offer_id":47839495979226,"sku":"THP-D3K2-60","price":21.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0814\/5158\/1658\/files\/thp_d3-k2.png?v=1778047690","url":"https:\/\/truehealthprotocol.health\/products\/vitamin-d3-5000-iu-k2-mk-7-100mcg","provider":"True Health Protocol","version":"1.0","type":"link"}