August 18, 2011
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View it in your browser. The effect of vitamin D on estrogen levels in women
I have written before that vitamin D increases testosterone levels in men. It is not a minor effect.
Pilz S, Frisch S, Koertke H, Kuhn J, Dreier J, Obermayer-Pietsch B, Wehr E, Zittermann A. Effect of vitamin D supplementation on testosterone levels in men. Horm Metab Res. 2011 Mar;43(3):223-5.
Now, a group in Canada, led by Dr. Julia Knight at Mount Sinai Hospital, discovered that administration of 24,000 IU/week for four weeks was associated with lower estrogen levels and progesterone levels. Per 4 ng/ml increase in vitamin D, progesterone levels decreased by 10% and estrogen decreased by 3%. Unlike men, the study was confounded by what estrous cycle phase the women were in.
Knight JA, Wong J, Blackmore KM, Raboud JM, Vieth R. Vitamin D association with estradiol and progesterone in young women. Cancer Causes Control. 2010 Mar;21(3):479-83.
The favorable implications for breast cancer come immediately to mind, but as an old GP, I can tell you that lower female hormones sometimes help women in all kinds of ways, including psychologically. I suspect the women also became more fertile.
The studies about vitamin D are pouring out, and I am happy to summarize these studies and offer my personal insight to the general public through these pieces. Soon, these write-ups will only be offered in full to members of the blog we're launching (by the end of the month!). This new system will help the Vitamin D Council continue its work and support our programs. So take a minute, consider donating or becoming a member. It is not expensive, but it really does make my day to see that people still care in these rocky economic times.
-John J. Canne