A clinical review published in April in The Journal of the American Osteopathic Association found that up to a billion people worldwide don’t have sufficient levels of vitamin D for optimal health—mostly due to sunscreen.
Other common health conditions that inhibit the body’s absorption of vitamin D and lead to or worsen deficiencies include type 2 diabetes, kidney disease, and Crohn’s and celiac disease.
How Much Vitamin D is Too Little?
Vitamin D insufficiency is defined as between 21 and 30 ng/ml and deficiency is considered below 20ng/ml by the Endocrine Society.
“People are spending less time outside and, when they do go out, they’re typically wearing sunscreen, which essentially nullifies the body’s ability to produce vitamin D,” said Kim Pfotenhauer, DO. Pfotenhauer is an assistant professor at Touro University and served as a researcher on this study. “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.”
Vitamin D: What Is It and Why Is It So Crucial?
Vitamin D is actually a hormone that is produced when your skin is exposed to sunlight. Almost every cell in in the human body has vitamin D receptors, in part because vitamin D is essential to so many functions of the body:
- Cell growth modulation
- Neuromuscular and immune function
- Inflammation reduction
Two primary symptoms of low vitamin D include muscle weakness and bone fractures.
However, low levels of vitamin D are suspected to play a role in a variety of serious health conditions. Ongoing research is examining whether vitamin D
deficiency has a role in:
- Multiple sclerosis
- Autoimmune disorders
- Respiratory disease
- Cardiometabolic disease
Boosting Your Vitamin D With Sunshine
All you need to do to increase and maintain healthy vitamin D levels is to spend between five and 30 minutes outdoors in midday sun at least twice each week.
The reason for the time range is that it depends on your skin pigmentation and where you live. The lighter your skin, the faster you synthesize vitamin D. Most important is that you skip the sunscreen for these deliberate sessions in the sun, because SPF 15 or higher slashes vitamin D3 production by a whopping 99%!
You also don’t need to don a bathing suit or lie down to soak in the sun. “You don’t need to go sunbathing at the beach to get the benefits,” said Dr. Pfotenhauer. “A simple walk with arms and legs exposed is enough for most people.”
Vitamin D Supplements
If for any reason sun exposure and food sources aren’t enough to get your levels up, Dr. Pfotenhauer said supplements are an effective option. He recommends you talk to your doctor and, of course, take the supplement as directed.