The importance of getting enough vitamin D to maintain strong and healthy bones is something that has been drilled in all of us, particularly women, for years. Now, however, researchers are finding that the sunshine vitamin is important in maintaining other aspects of your health — even fertility.
WHAT IS VITAMIN D?
Vitamin D is not found in many foods, only fortified dairy products, fish, eggs and organ meats. The best way to get vitamin D is via the sun — it is produced in the skin when there is adequate exposure to sunlight. The vitamin promotes intestinal absorption and metabolism of calcium and phosphorous, and research is finding that it is important to the immune system, as well as other physiological functions in the body.
People in warmer climates who can expose unprotected skin to two 15-minute sessions of sunlight each week typically do not need vitamin D supplements. However, those who live in colder climates or deal with smog and/or cloud cover may have a deficiency. Surprisingly, some researchers estimate that in the United States and Europe more than two-thirds of the population is deficient in vitamin D.
VITAMIN D, FERTILITY AND IVF SUCCESS
Today, scientists understand that vitamin D plays a much larger role in overall health because it not only affects the cells that live in the bone, but it affects many different cells in many different organs of the body. Two large studies published in the spring of 2014 found that people with low vitamin D levels are more likely to die from cancer and heart disease and to suffer from other illnesses
Now, a very recent large study published in the Journal of Clinical Endocrinology & Metabolism.has found that in patients undergoing in vitro fertilization (IVF), having a serum vitamin D level of 20 ng/mL or more was associated with a significantly greater chance of obtaining three or more high-quality embryos, successful embryo implantation and achieving clinical pregnancy.
The study evaluated 335 women referred to an IVF clinic in Milan, Italy. Of these women, 154 were vitamin D deficient. The clinical pregnancy rate was 20 percent— 30 out of 154 among the women who had vitamin D deficiency, compared with 31 percent — 56 out of 181 — in those with sufficient vitamin D levels. The study could point to the benefits of vitamin D supplementation in women undergoing IVF. Another study involving women using young donated eggs found the same results regarding lower embryo implantation with low vitamin D levels.
VITAMIN D SUPPLEMENTATION
The current recommended daily allowance (RDA) of vitamin D is 600 international units (IU) daily for people ages 1 to 70 and 800 IU for those who are older. The American Association of Clinical Endocrinologists and the Institute of Medicine recommend 800 to 1,000 IU of vitamin D for the average man and premenopausal woman under 70 years old.
So how can you make sure you are getting enough vitamin D?
- An average multivitamin contains around 400 IU of vitamin D. Choose USDA graded supplements that contain vitamin D3, which is better utilized by the body.
- Get 10 to 15 minutes of sun on your uncovered face and arms twice a week. This can be much more difficult when the weather is cold and the sun is less intense. Thus supplementation becomes even more important.
- Some of the foods that are rich in vitamin D, such as salmon, tuna and mackerel, are also warned against eating during pregnancy. Make sure you are drinking vitamin D fortified milk. Beef liver, cheese and egg yolks also have vitamin D.