I've written about this before, but wanted to revisit the topic since our network member Lesli Bitel-Koskela of Harmonic Nutrition just sent me a new study reinforcing the importance of vitamin D for fertility. The study Lesli sent is nice, because both the test and control groups were on metformin. That means the results reinforce that you can't give up on good nutrition simply because your physician has scripted a medication. Nutrition and medicine are not either/or options; they are important to use together in order to achieve their maximum effect. One hundred women with PCOS who had not been able to conceive, when given calcium and vitamin D supplements, lost weight, improved menstrual regularity, and had improved follicle quality and fertility. When the study started, 83% of the women studied had a measurable vitamin D deficiency; 35% of these women were rated as"severely deficient". After treatment, 74% of the women had normal vitamin D levels. I cannot reinforce enough; if you are pursuing infertility treatment, and your physician has not ordered a vitamin D level, s/he may be missing a crucial part of the puzzle. Demand it. It is relatively inexpensive, and may save you a fortune in infertility treatment. Firouzabadi RD, Aflatoonian A, et al. Therapeutic effects of calcium & vitamin D supplementation in women with PCOS," Complement Ther Clin Pract, 2012 May; 18(2):85-8.