Vitamin D for humans is obtained from sun exposure, food and supplements. Living in Arizona one might think they would definitely get enough exposure to sunlight; but, if you are wearing sunscreen, as you should be, it blocks around 97% of your body’s vitamin D production. In addition, other factors such as cloud cover, air pollution and skin pigmentation can hinder how much we absorb. For example, dark pigment in the skin reduces the skin’s ability to synthesize vitamin D from sunlight by 95%. Unfortunately, the benefits of exposure to UVB radiation cannot be separated from the harmful effects. So what are your other options? And how much do you need?
Very few foods in nature contain vitamin D. The flesh of fish, such as salmon, tuna, and mackerel, and fish liver oils are among the best sources, with small amounts of vitamin D found in beef liver, cheese, and egg yolks. Vitamin D in these foods is primarily in the form of vitamin D3 (cholecalciferol) and its metabolite 25(OH)D2. Some mushrooms provide vitamin D2 (ergocalciferol) in variable amounts.
Most of the vitamin D in food is fortified, for example, almost all of the U.S. milk supply is fortified with 100 IU/cup of vitamin D. Other dairy products made from milk, such as cheese and ice cream, are generally not fortified. Ready-to-eat breakfast cereals often contain added vitamin D, as do some brands of orange juice, yogurt, and margarine.
If you do not eat vitamin D rich foods often, or perhaps don’t eat enough, supplements of D3 are your other option. The current recommended intake of vitamin D is 200 IU for those up to age 50; 400 IU for people 51-70; and 600 IU for those older than 70 (requirements increase with age because older skin produces less vitamin D). These recommendations date back to 1997 and many additional studies have been published since that document the effectiveness of higher levels of vitamin D, the evidence is mounting that we need more. The safe upper limit for vitamin D is 2,000 for children, adults and pregnant and lactating women. Some experts have suggested increasing the recommended amount to more than 2,000, but this would need to be evaluated by your doctor on a case by case basis.
Chances are, most people are not getting enough vitamin D for good health. To be certain, call and schedule an appointment to have your vitamin D levels tested. You want to ask for the test that measures the circulating form of vitamin D, the test is referred to as 25[OH]D, or 25-hydroxyvitamin D.
Dr. Allen would be more than happy to assist you with evaluating your levels and developing a proper treatment plan.
Please call (480) 832-SKIN (7546) to make an appointment.