Vitamin D is a fat-soluble vitamin that comes from sun exposure, certain foods and supplements. Vitamin D plays an important role in the body, helping to promote calcium absorption, boosting cell growth, aiding immune and neuromuscular function and reducing inflammation.
Although ultraviolet rays from the sun do aid in the body’s ability to make vitamin D, the risk of skin damage and skin cancer is too great for most dermatologists to recommend even brief periods of unprotected sun exposure.
Skin cancer is the most common cancer in the US, with more than 3 million cases blamed on natural and artificial ultraviolet light exposure alone.
Most dermatologists agree the best way for people to get vitamin D is from a healthy diet. Salmon, mackerel and some mushrooms (such as portabellas) that have been exposed to ultraviolet light are all loaded with vitamin D. Tuna packed in water, sardines in oil, dairy products and juices that have been fortified with vitamin D, beef liver, egg yolks and cheese are also considered good sources of the vitamin.
The National Academy of Sciences Institute of Medicine guidelines suggest the recommended dietary allowance of vitamin D is 600 IU/day for persons up to age 70, and 800 IU/day for those aged 71 and older. However, intake should be based on individual needs and should take into account medical considerations.
Higher doses of vitamin D may be recommended for those at risk of vitamin D deficiency including dark-skinned individuals, the elderly, those with photosensitivity, obese individuals, persons with limited sun exposure, and those with fat malabsorption issues.
Vitamin D is not readily excreted from the body and excessive intake of the vitamin can lead to serious health effects. Vitamin D supplements can also interact with certain types of medication, so talk with your doctor before making them part of your daily routine.