Benefits of Sunlight

Some have wondered if the success that the open-air hospitals had in treating influenza patients was due to sunshine rather than fresh air. One could probably research and debate this for a long time because they both have big benefits. 

The best known benefit of sunshine is its ability to boost the body’s vitamin D supply. There are at least 1,000 genes which govern nearly every tissue in the body are now thought to be regulated by 1,25-dihydroxyvitamin D3 [25(OH)D], the active form of the vitamin. Several of these tissues are involved in calcium metabolism and neuromuscular and immune system functions. Low levels of vitamin D are linked to several kinds of cancer, multiple sclerosis, type 1 diabetes, and metabolic syndrome. People living at higher altitudes throughout the world are at higher risk of hypertension and patients with cardiovascular disease are often found to be deficient in vitamin D. Sun exposure and higher levels of 25(OH)D may confer protection against other illnesses such as rheumatoid arthritis, asthma, and infectious diseases.

What should our vitamin D levels be? Many experts today believe that levels of 25(OH)D between 40 and 60 ng/mL maximize protection against cancer and other chronic diseases. Anything under 20 ng/mL is considered a vitamin D deficiency. A couple of years ago a physician friend in Spokane told me that he had started testing a large number of his patients for vitamin D levels and had not found even one with optimal levels. 

We live our lives largely indoors. In the beautiful Pacific Northwest, nearly half of the year the sun is not at a good angle to allow our bodies to produce vitamin D. Many of us likely need to take a vitamin D supplement in addition to getting more sunshine. Many experts are recommending 2,000 IU vitamin D3 plus 12-15 minutes of midday sun with 40% of your skin exposed every day or 4,000 IU vitamin D3 every day without sun exposure.

The “take-home” message? Get your vitamin D level checked if you haven’t already. Add a supplement if your levels are low. Get outside and responsibly enjoy some sunshine while it lasts.