by Leia Anderson

The best-known function of vitamin D is to maintain the body’s balance between calcium and phosphorus and keep bones strong. Severely low levels of vitamin D can cause rickets (weak and deformed bones) in children and osteomalacia (softening of the bones) in adults. However, vitamin D plays many roles to support good health, such as cardiovascular function, immune system function, muscle strength and brain development.

Research suggests that low levels of vitamin D are linked to cancer, diabetes, hypertension, multiple sclerosis, lupus, rheumatoid arthritis, Hashimoto’s thyroiditis and skin pathologies such as dermatitis, vitiligo and psoriasis. Vitamin D also plays a role in seasonal affective disorder (SAD) and depression.

It is easy to get vitamin D levels checked and optimized. A simple blood test can be ordered by a primary care doctor or naturopathic doctor. If levels are found to be low, physician recommendations may include increasing safe sun exposure and supplementing the diet with vitamin D3, depending upon age and weight. It’s important to have follow-up testing after beginning a regimen that includes supplements in order to determine if levels are correct.

It’s best to get vitamin D from the sun, if possible, because vitamin D produced in the skin lasts two to three times longer than ingested vitamin D. The nonprofit Vitamin D Council sun exposure recommendations are five to 15 minutes per day, three times per week, during the hours of 10 a.m. and 3 p.m., with at least 35 percent of skin exposed to the sun. Sunscreens block the skin’s absorption of ultraviolet B (UVB) radiation, so consider delaying the application of sunscreen until after the first 15 minutes of sun exposure.