Long-term Vitamin D insufficiency has been linked to osteomalacia, a metabolic bone condition characterized by a reduced mineralization of bone.
A study out of the University of Pittsburgh Graduate School of Public Health, the results of which were presented at the annual meeting of the American Society for Bone and Mineral Research in 2007, found that the risk of hip fractures was 77 per cent greater in women in the study who had the lowest levels of Vitamin D.
The North American/Western diet is typically poor in vitamin D. Very few foods, with the exception of fatty fish, are rich in Vitamin D. Epidemiological studies have demonstrated that populations such as Japanese achieve sufficient Vitamin D intake because their diets are rich in Vitamin D sources such as salmon, tuna, and mackerel.
Foods such as milk are fortified with Vitamin D in an attempt to ensure that people meet their daily, recommended intake of Vitamin D. Specifically, it was a measure designed to eliminate bone rickets, a condition that was prevalent at one point in history because of Vitamin D deficiency. The traditional recommendation had been 400 International Units per day.
More recently, organizations such as the Canadian Cancer Society revised its recommendation for daily Vitamin D intake because of more and more evidence of the protective effect that Vitamin D can have in preventing the development of cancer, namely colorectal. Its recommendation is that adults consume 1,000 IUs of Vitamin D.
Sunlight Exposure Poses Threats
Another source of Vitamin D are the ultraviolet rays that the sun emits. Vitamin D synthesis occurs naturally when the skin is exposed to sunlight and its powerful ultraviolet rays. Adequate sunlight exposure sounds like a simple solution to Vitamin D deficiency, but increasing exposure to sunlight carries its own risks. Reputable organizations such as the American Academy of Dermatology (AAD) note that ultraviolet exposure in the absence of sunscreens is a risk factor for the development of skin cancer as is the use of indoor tanning devices.
Organizations like the AAD recommend routine use of a broad-spectrum sunscreen and stress that individuals should look to dietary sources of Vitamin D, either through consuming foods that are rich in Vitamin D, are fortified with Vitamin D, and/or through the intake of Vitamin D supplements.
No Consensus on Daily Vitamin D Doses
With information evolving over the optimal amount of Vitamin D needed, it's premature to contemplate basking in the sun to elevate Vitamin D levels. It would be more prudent to seek out dietary sources of Vitamin D and consider taking a daily Vitamin D supplement, particularly if individuals are at high-risk of developing a condition like osteoporosis.
