Widespread
vitamin D deficiency likely due to sunscreen use, increase of chronic diseases
American Osteopathic Association
Results from a clinical review published in The Journal
of the American Osteopathic Association find 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.
The study also found that 95 percent of African American adults
may have vitamin D deficiency or insufficiency. Vitamin D variations among
races are attributed to differences in skin pigmentation.
"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, assistant
professor at Touro University and 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."
Dr. Pfotenhauer also 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 metabolize vitamin D from
food sources.
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.
People exhibiting these symptoms or who have
chronic diseases known to decrease vitamin D, should have their levels checked
and, if found to be low, discuss treatment options. However, universal
screening is likely neither necessary nor prudent absent significant symptoms
or chronic disease.
Increasing and maintaining healthy vitamin D levels can be as
easy as spending 5-30 minutes in midday sun twice per week. The appropriate
time depends on a person's geographic location and skin pigmentation -- lighter
skin synthesizes more vitamin D than darker skin.
It is important to forgo
sunscreen during these sessions because SPF 15 or greater decreases vitamin D3
production by 99 percent.
"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."
Food sources such as milk, breakfast cereals, and Portobello
mushrooms are also fortified with vitamin D. Dr. Pfotenhauer said supplements
are a good option, as they are effective and pose few risks, provided they are
taken as directed and a physician is consulted beforehand.
Research is ongoing to determine whether vitamin D deficiency
has a role in multiple sclerosis, autoimmune disorders, infections, respiratory
disease, cardiometabolic disease, cancer, and fracture risk.
"Science has been trying to find a one-to-one
correspondence between vitamin D levels and specific diseases," said Dr.
Pfotenhauer. "Given vitamin D's ubiquitous role in the body, I believe
sufficient vitamin D is more about overall health. Our job as osteopathic
physicians is to recognize those patients that need to be tested and treat them
accordingly."
Currently, insufficiency is defined as between 21 and 30 ng/ml
and deficiency is considered below 20ng/ml by the Endocrine Society.
