You’ve heard it before: “go outside; get some sun to boost your vitamin D production!”
Vitamin D is produced in our bodies when exposed to UV, or ultraviolet, radiation in the presence of sunlight. It is important for protection of the nervous system, bone and immune health, and muscle strength and function. The recommendation for Vitamin D intake for adults is 15 mcg/day (19-70 years of age) and 20 mcg/day (71 years of age and older). A deficiency in this vitamin may lead to impaired immune and muscle function, mood disorders, fatigue, bone and muscle pain, impaired wound healing, and cardiovascular disease.
If you are a dark-skinned individual living in the northern or midwestern regions of the United States or at higher latitudes, you may be at risk of decreased vitamin D production, especially during the wintertime. During the winter, days have shorter sunlight time, and generally cloudier and darker. In colder zones, people stay indoors more often and layers of clothing limit skin exposure to sunlight. Overall, your ability to produce vitamin D is reduced during this time of the year. Due to increased needs, your primary care provider may recommend obtaining vitamin D in supplemental form or through increased consumption of vitamin D-rich foods. Although most foods are not naturally high in vitamin D, many foods and beverages are now fortified with added vitamin D. Eating these fortified foods with 10% or more of the daily value per serving can help you meet your needs but, check labels to make sure vitamin D is listed. Some of these fortified foods include ready-to-eat cereal, egg yolk, milk, yogurt, orange juice, and fish such as cod, salmon, and tuna.
What about phototherapy? You may have heard of S.A.D. lamps and red-light therapy. They claim to improve seasonal affective disorder among other ailments. Although exposure to artificial UV light at specific wavelengths can stimulate the production of vitamin D, these products aren’t designed to mimic sunlight UV production. Red light therapy may indirectly improve vitamin D production by protecting an optimizing skin in a way that allows you to absorb UV light longer with a decrease in the negative effects of prolonged sun exposure.
The Bottom Line: symptoms of vitamin D deficiency are often subtle and can be overlooked. It is helpful to ask your healthcare professional for a blood test and evaluate your current levels. Maximizing your sun exposure and eating vitamin D-rich foods are simple ways to ensure adequate vitamin D production and intake for optimal health this winter.