Vitamin D

D3·Cholecalciferol 🟢 Strong

A fat-soluble vitamin central to bone and immune health; deficiency is common in people who stay indoors.

⚠ InteractionsSee cautions below; consult your physician for specifics.⚠ High-doseSee cautions below; consult your physician for specifics.⚠ KR/US unitsSee cautions below; consult your physician for specifics.

Reviewed by Dr. Sungwoong Jung · Last reviewed Jul 16, 2026

Key benefits

Helps gut absorb calcium for strong bones

Modulates immune-cell function

Linked to muscle strength in older adults

How it works

Evidence

🟢 StrongClear bone benefit when correcting deficiency

🟡 Moderate / mixedLimited disease-prevention benefit if not deficient (VITAL)

The same nutrient can differ for "correcting deficiency" vs "general prevention."

Suggested use

600–2000 IU/day is common, taken with a fatty meal; personalize with a blood test.

A general suggestion, not a prescription.

Cautions & interactions

Caution with high blood calcium/stones. Thiazide diuretics may raise calcium.

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Korea vs USA

🇰🇷 Korea

MFDS mark · IU · pharmacy/Olive Young

🇺🇸 USA

USP/NSF · IU+mcg · Amazon/iHerb

References

NIH ODS — Vitamin D ↗Manson JE et al. VITAL, NEJM 2019 ↗

Grades/refs re-verified at each update (draft).

Calcium Calcium The key mineral for bones and teeth; especially important for postmenopausal women. 🟢 Strong Bone·Joint Vitamin K2 Vitamin K2 A fat-soluble vitamin that helps direct calcium into bone. 🟡 Moderate Bone·Joint Magnesium Magnesium An essential mineral for muscle, nerve, and sleep; forms differ in absorption and use. 🟡 Moderate Muscle·Nerve

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Disclaimer — This content is for general information and suggestion only and does not replace medical diagnosis or treatment. Consult a doctor or pharmacist if you have a condition or take medication.