My vitamin D is low — what should I do?
Most adults need 2,000–5,000 IU daily of vitamin D3 with co-factors (magnesium, K2) to reach the 40–60 ng/mL range. Recheck at 8–12 weeks. Severe deficiency warrants higher provider-directed loading.
Full answer
25-hydroxyvitamin D under 30 ng/mL is insufficient; the target optimization range is 40–60 ng/mL. Repletion is usually 2,000–5,000 IU daily of vitamin D3 with adequate magnesium and dietary vitamin K2. Severe deficiency (<20 ng/mL) is corrected with provider-directed loading. Calcium and PTH are reviewed at baseline. Sun exposure contributes but is unreliable. The level is rechecked at 8–12 weeks and then on the recalibration cadence. Vitamin D supports bone, immune, and hormonal function and is a no-cost lever for most candidates.
Educational. Not a substitute for individualized provider review.
- Methodology — Primary source · oMeds
- Reviewed by Dr. Laura Purdy, MD, MBA · Clinical Director, oMeds · Last reviewed 2026-06-03