This month's theme of the Her… magazine is “red hot.” one of the hottest topics in health these days is vitamin D.
I was taught in medical school that vitamin D was needed for bone health but, as research in the last several years has shown, many other organ systems in our body seem to benefit when vitamin D is at the appropriate level. so let's learn more about this important vitamin.
what is vitamin D?
Vitamin D is a fat-soluble vitamin that helps the body absorb calcium as well as regulate the level of calcium and phosphorus in the blood.
why is it important?
Higher levels of vitamin D have been shown to reduce fracture risk and increase bone density. More recent studies suggest that sufficient vitamin D levels are associated with a lower risk of some cancers, the progression of osteoarthritis, multiple sclerosis, high blood pressure and diabetes. it also may help with weight loss, immune function and depressive symptoms. Vitamin D deficiency in pregnancy may play a role in the growth of the baby as well as bone and brain development.
How is a vitamin D level tested?
Vitamin D testing requires blood to be drawn. Results are given as numbers and typically look like this:
Deficiency: <20 ng/ml
Insufficiency: 20-32 ng/ml
Sufficiency: 33-80 ng/ml (in sunny countries 54-90 is considered normal)
Excess: >100 ng/ml
these guidelines have changed over the years and there is still much discussion about what the appropriate level is to obtain. Older guidelines were lower and were based on what level was needed to prevent rickets. now that we understand there are other health benefits, we need to determine at what level are these benefits obtained.
what are good sources of vitamin D?
most diets do not provide us with sufficient vitamin D. Fish, eggs and milk fortified with vitamin D are good sources.
The best source is from sun exposure to the skin. however, because of the risk of skin cancer and recommended use of sunscreen, many are not getting adequate vitamin D from that source. For me, moderate exposure to sun without sunscreen for about 15 minutes three days a week is what I try to get. I am not promoting tanning or getting a sunburn, just moderate exposure.
you are likely going to need to take a supplement to get your levels in the sufficient range. The Food and Nutrition Board at the Institute of Medicine recommends the following dietary intake of vitamin D for women:
Age 14-50: 200 IU/day
Age 51-70: 400 IU/day
My personal experience as a clinician and patient has shown that many women need much higher levels of vitamin D initially to get their levels in the sufficient range and then they can take lower doses. most supplements prescribed will be in a pill form. If you can't tolerate that (some people get an upset stomach from it), I have had great success locally at Healthwise Pharmacy with a highly concentrated liquid form of vitamin D by a company called Vinco, Inc. you only have to take a tiny amount and it does not upset my stomach. it has raised my levels to the sufficient range.
During pregnancy, we do not routinely check vitamin D levels, but that may change in the future as more is understood. Until then, if you desire to know your level you can ask to have it drawn. If it shows you are deficient, then you may need to take a slightly higher dose.
I know this may be confusing, but science evolves. we are taught in medical school “First, do no harm.” we always must weigh the risks and benefits of what we recommend. I think it is very reasonable to get your vitamin D level checked and, based on that result, have your health-care provider recommend a particular dose for you. A repeat level after a few months will then allow him or her to modify your dose to keep you in the sufficient range.
Dr. Susan Bane is a board-certified obstetrician-gynecologist and an adjunct professor in East Carolina University's Department of Exercise and Sport Science.