A vitamin which has received a lot of interest lately, for a host of reasons, is vitamin D. Various studies have shown the importance of vitamin D in the prevention of aggressive forms of prostate cancer, colon cancer and even skin cancer. It acts as an insulin stimulator to help deter diabetes. It can help to offset the effects of PMS as a regulator of the hormone, estrogen. It boosts serotonin which has been found to help depression. It is also important to understand the role of vitamin D in calcium absorption. Without vitamin D, calcium does not find its way to the bones. Not only does it aid in calcium absorption but in strengthening the muscles which gives added mobility to the elderly. The significance of this can be seen when we realize that falls are the largest cause of injury related deaths in nursing homes.
For all of these reasons, the importance of getting the proper amount of vitamin D is becoming more and more apparent. This, however, presents a dilemma. The single best way that we receive vitamin D is through sunshine. In recent years, it is becoming clear that Americans are not getting enough vitamin D. This has been due, in part, to the increased use of sunscreens. Sunscreen blocks the absorption of vitamin D in the skin. Does this mean we should stop using sunscreen? No, absolutely not. Some studies suggest that we spend 5-10 minutes, three times a day , in the sun without sunscreen.
Other studies suggest that we spend 10-15 minutes, one to two times a day, in the sun without sunscreen. I think it is clear that only small doses of being exposed to the sun, without sunscreen are recommended.
There are some foods, although not many, which provide vitamin D. These would be fatty fish, milk, fortified orange juice and fortified cereals. Mushrooms that are sun grown are also a good source of vitamin D. Green leafy vegetables are not a good source of vitamin D. Because of this, a daily supplement is recommended. Traditionally, 200 I.U.s were the recommended dose but new studies are suggesting anywhere from 600-800 I.U.s as a minimum dose. Up to 2,000 I.U.s a day has not been shown to pose a toxicity risk but there is really no reason to take this much.
Given the known benefits of vitamin D, all of us, especially as we age, should pay as close attention to this vitamin as we do calcium.