People who try to stay bronze with
the help of a tanning bed tend to have higher blood levels
of vitamin D than those shun the salon, according to a new
The findings, say the study
authors, suggest that a regular appointment at the tanning
salon may have health benefits -- though they and other experts
don't recommend that people start tanning in order to boost
their vitamin D levels.
The study of 156 adults found
those who regularly soaked up the artificial rays of a tanning
bed had a 90 percent higher average vitamin D concentration
in their blood. The tanners, who frequented the salon at least
once a week for 6 or more months, also had greater bone density
in the hips.
The study, published in the
American Journal of Clinical Nutrition, was partially financed
by the UV Foundation, which is funded by the Indoor Tanning
Association, an industry group.
A precursor to vitamin D exists
naturally in the skin, and exposure to the sun's ultraviolet
(UV) rays touches off a chemical process that creates the
usable form of the vitamin. Because vitamin D is needed for
proper calcium absorption, the nutrient is vital to bone health.
There is also a body of research suggesting vitamin D helps
protect against certain cancers and some autoimmune diseases,
such as type 1 diabetes and multiple sclerosis.
But the fact that UV radiation
is the major cause of skin cancer, as well as the major source
of vitamin D, has made for a controversy over how much sun
-- or artificial sun -- people should get.
The senior author on the new
study, Dr. Michael F. Holick of Boston University School of
Medicine, has for some time advocated that people spend a
short amount of time outside, without sunscreen, several days
a week -- with the amount of time depending on factors such
as latitude and a person's skin sensitivity.
For a white person in Boston,
that might mean 10 minutes in the sun, while a darker-skinned
person would need longer exposure.
"I'm not an advocate of tanning,"
Holick stated in an interview, noting that some people --
those with particularly sun-sensitive skin that never tans
-- should avoid tanning salons.
However, Holick said, the new
findings indicate that there is a "health benefit above and
beyond feeling good" from tanning beds that emit UVB light,
the form of UV radiation that triggers vitamin D production.
Moreover, Holick said, the
results add to research showing that many Americans may be
low in vitamin D. A number of studies have found fairly high
rates of vitamin D deficiency in the U.S., particularly among
African Americans, who need more UV exposure to produce the
Among the 50 tanning-salon
patrons in Holick's study, 8 percent were deemed deficient
in vitamin D, compared with 41.5 percent of non-tanners.
But dermatologists, concerned
about skin cancer, balk at the idea that many Americans need
to increase their UV exposure for the sake of vitamin D.
The American Academy of Dermatology
advises people to avoid outdoor activities when the sun's
rays are strongest -- between 10 a.m. and 4 p.m. -- and to
wear sunscreen with SPF 15 or higher whenever they're outside.
The group has also urged a ban on the use of tanning equipment
for non-medical purposes.
"You get plenty of UV light
in your normal daily activities," said Dr. Darrell S. Rigel,
a clinical professor of dermatology at New York University
in New York City.
Even when protected with sunscreen,
he noted in an interview, the skin still absorbs UV rays and
churns out vitamin D.
Anyone concerned about getting
enough of the nutrient, Rigel said, can get more by taking
vitamin supplements and from vitamin D-fortified milk or other
dietary sources of the vitamin. Some cereals and juices are
also D-fortified, and fatty fish such as salmon and tuna are
With UV radiation known to
be a carcinogen, Rigel said, "there's no reason to go to a
Holick said that people who
do not wish to get more sun should take supplements to increase
their vitamin D levels, as it may be tough to consume enough
milk and fatty fish.
SOURCE: American Journal of
Clinical Nutrition, December 2004.