Research

Hormonal

Increasing vitamin D intake from 100 IU to 500 IU daily reduces late wintertime spinal bone loss and improves net spinal bone density in healthy postmenopausal women consuming approximately 800 mg of calcium daily.

If you are a postmenopausal woman, ensure you are getting about 500 IU of Vitamin D daily, especially during winter months. This is particularly important if you are also taking calcium supplements (around 800mg total daily). This combination helps prevent the specific bone loss that happens when sunlight is scarce.

GoodSupportsHIGH confidence
In healthy postmenopausal women residing in Massachusetts and taking calcium supplements to approximately the Recommended Dietary Allowance (RDA) (29), increasing vitamin D intake from 100 to 500 IU daily produced an overall benefit in spinal bone mineral density. Spinal bone loss between December and June was less in the vitamin D-treated group than in the placebo group.
Bess Dawson‐Hughes et al. · Annals of Internal Medicine · 1991

Why this rating

Double-blind, placebo-controlled, randomized trial with a large sample size (n=249) and precise measurement methods (DEXA), though limited to one year and specific latitude.

Source

Effect of Vitamin D Supplementation on Wintertime and Overall Bone Loss in Healthy Postmenopausal Women

Bess Dawson‐Hughes et al. · Annals of Internal Medicine · 1991

DOI 10.7326/0003-4819-115-7-505

rct · n=249Cited 506×
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DOI resolved against Crossref · corpus check 2026-06-10

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