Sunscreens may lead to vitamin D deficiency, says study

Applying sunscreen may make you deficient in vitamin D, increasing your risk of muscle weakness and bone fractures, new research warns. 

Researchers from Touro University California in the US found that nearly 1 billion people worldwide may have deficient or insufficient levels of vitamin D due to chronic disease and inadequate sun exposure related to sunscreen use.

"People are spending less time outside and, when they do go out, they are typically wearing sunscreen, which essentially nullifies the body's ability to produce vitamin D," said Kim Pfotenhauer, assistant professor at Touro University. 

"While we want people to protect themselves against skin cancer, there are healthy, moderate levels of unprotected sun exposure that can be very helpful in boosting vitamin D," Pfotenhauer said. 

Chronic diseases like Type 2 Diabetes and those related to malabsorption, including kidney disease, Crohn's and celiac disease greatly inhibit the body's ability to metabolise vitamin D from food sources, researchers said. 

Considered a hormone rather than a vitamin, vitamin D is produced when skin is exposed to sunlight. 

Vitamin D receptors are found in virtually every cell in the human body. As a result, it plays a wide role in the body's functions, including cell growth modulation, neuromuscular and immune function and inflammation reduction. 

Symptoms for insufficient or deficient vitamin D include muscle weakness and bone fractures. 

Increasing and maintaining healthy vitamin D levels can be as easy as spending 5-30 minutes in midday sun twice per week, researchers said. 

"You do not need to go sunbathing at the beach to get the benefits. A simple walk with arms and legs exposed is enough for most people," Pfotenhauer said. 

"Science has been trying to find a one-to-one correspondence between vitamin D levels and specific diseases. Given vitamin D's ubiquitous role in the body, I believe sufficient vitamin D is more about overall health," she said. 

The findings were published in The Journal of the American Osteopathic Association.