Open Community Question @GraniteHiker_NH • 45-59F • 2,000 IU D3 / 120 mcg MK-7 / • Week 12

▲ 41 Helpful • 2 Peer Replies

Do I need K2 and magnesium with vitamin D3, and how do I dose them without overshooting?

Patients often ask whether D3 works without K2 and magnesium. Here is what the labels and data support. Vitamin D3 raises 25(OH)D by roughly 1 ng/mL per 100 IU/day, though response varies with body weight and baseline level. So 2,000 IU/day typically moves a level of 18 ng/mL to about 30-38 ng/mL over 8-12 weeks. Magnesium is a cofactor for the enzymes that activate vitamin D. Men need 400-420 mg/day and women 310-320 mg/day from all sources. The supplemental upper limit is 350 mg/day elemental, and magnesium glycinate usually supplies about 14% elemental magnesium by weight. Typical MK-7 doses are 90-180 mcg/day. Evidence that K2 improves bone or arterial outcomes is mixed, and it is not required for D3 to work. Anyone on warfarin should not add K2 without prescriber monitoring. Recheck 25(OH)D after 12 weeks, not sooner.

⚕ Pinned FDA / NIH / PubMed Clinical Context • Siriporn Wattana — Literature & Label Auditor

NIH ODS lists the vitamin D UL at 4,000 IU (100 mcg)/day for adults and the supplemental magnesium UL at 350 mg/day. The IOM treats 25(OH)D of 20 ng/mL (50 nmol/L) as adequate for most people, while the Endocrine Society suggests at least 30 ng/mL for those at risk of deficiency.

Connected Clinical Guides: Condition: Vitamin D Deficiency Condition: Osteopenia Rx: Ergocalciferol Rx: Levothyroxine Supplement: Vitamin D3 Supplement: Vitamin K2 Mk7

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Verified Peer Replies (2)

@SonoranSunrise_AZ • Verified Cohort Member • Week 18

Check the label for elemental magnesium, not the compound weight. A 1,000 mg magnesium glycinate capsule may supply only about 140 mg elemental. Split doses across the day, and reduce the dose if stools loosen. People with reduced kidney function should ask a prescriber before taking magnesium.

@MidwestCardioDad • Age 60+ • Week 14

I took D3 alone for 3 months and my level rose from 22 to 31 ng/mL. I added magnesium at night and felt less muscle cramping. I skipped K2 because I take a blood thinner.