Experts clash over sun exposure to boost vitamin D

[Guest guest]

May 19, 2004

Experts clash over sun exposure to boost vitamin D

Boston, MA - An advocate of moderate exposure to the sun to satisfy the

body's requirement for vitamin D has clashed with dermatologists who say it

is imperative that people protect themselves from ultraviolet (UV) radiation

[1].

" As a dermatologist who treats the ravages of skin cancer on a daily basis,

it is appalling to me that anyone in good conscience could make the claim

that intentional sun exposurefor any length of timeis beneficial, " says Dr

Darrel Rigel (New York University Medical Center, NY).

But that is exactly what Dr Holick (Boston University School of

Medicine, MA) is doing in his new book, The UV Advantage. Aimed at the

general public and on sale as of this month, the book has already created a

storm of controversy and has also led to a call for his resignation. In the

book, Holick claims that moderate exposure to the sun has powerful health

benefits and that current advice to avoid the sun has led to an epidemic of

vitamin-D deficiency.

" Many who practice dermatology and their supporters in the sunscreen

industry have scared the public right out of the sun, the best way to

produce the vitamin D that the body needs, " Holick maintains. " These

naysayers have ignored the mountain of peer-reviewed science that

demonstrates that moderate exposure to natural or artificial sunlight has a

powerful, beneficial impact on health. "

" There are important medical consequences of this continuing rhetorical

campaign of fear and exaggerated claims, " Holick maintains. " There is no

doubt vitamin D is the best way for the body to control abnormal cell

growth, " he says, stating that sun exposure could lead to:

* Improved bone health and prevention of osteoporosis, osteomalacia, and

rickets.

* Reduced risk of heart disease, stroke, and breast, colon, and other

cancers.

* Alleviation of skin disorders.

* Decreased risk of autoimmune disorders, including multiple sclerosis,

type 1 diabetes mellitus, and rheumatoid arthritis.

* Enhanced mental health and lessening symptoms of seasonal affective

disorder, premenstrual syndrome, and depression.

Some experts agree. Dr Heaney (Creighton University, Omaha, NE) says:

" Holick provides a much-needed antidote to the scare tactics of the skin

mafia. " Dr (University of California, Los Angeles and

Cedars-Sinai Medical Center) says that the book Holick has written " provides

the clinical community with the first balanced, unbiased view of the

benefits and dangers of sunlight exposure in the last 50 years. " Dr Jim

Leyden (University of Pennsylvania, Philadelphia) has known Holick for 25

years and describes him as " an incredibly creative person who's made some

really fundamental observations and discoveries in several areas, " adding,

" He's ahead of his time. "

Dermatologists are furious

But dermatologists are furious, as his views are in direct contrast to their

firm advice on UV protection. In a recent press release, the American

Academy of Dermatology (AAD) said that the reports of health benefits of

vitamin D from unprotected sun exposure are " unsubstantiated " and are

causing further confusion among the public. " For decades, dermatologists

have advised the public to practice proper sun protection to prevent skin

cancerand that same advice holds true today, despite any claims to the

contrary. "

The AAD advises everyone to practice a " comprehensive sun protection

program, including avoiding outdoor activities between 10 am and 4 pm when

the sun's rays are strongest, seeking shade wherever possible, wearing a

broad-spectrum sunscreen with a sun-protection factor (SPF) of at least 15

and reapplying it every 2 hours, and wearing sun-protective clothing. "

Separately, 2 medical institutions, the Mayo Clinic and the University of

Alabama at Birmingham, have recently issued press releases emphasizing the

need for sunscreen to reduce the risk of skin cancer. " Slather on the

sunscreen. . . . Remember this when enjoying summer outdoor activities:

there's no such thing as a safe tan, " warns the May issue of the Mayo Clinic

Health Letter.

Holick was even asked to resign from the dermatology department of Boston

University earlier this year, when the contents of the book were first

revealed. Although he hadn't trained as a dermatologist, Holick had been

asked to join the department because so much of his research focused on skin

conditions. But he was asked to leave in February by department chair Dr

Barbara Gilchrest, an authority on melanoma. In an interview with the Boston

Globe, she said that the book is " an embarrassment for this institution and

an embarrassment for him, " and added, " I read better things in ladies'

magazines. "

Gilchrest criticized his conclusions and suggested that his ties to the

tanning industry may have influenced his research. (The Indoor Tanning

Association is donating $150 000 for research over the next 3 years and has

hired a publicist to promote the book.)

The resignation is largely symbolic, the newspaper reported, as Holick

remains the director of the Bone Health Clinic at Boston University Medical

Center and is continuing to teach with no loss in salary. He commented at

the time that he was " being punished for challenging one of the dogmas of

dermatology " and contends that public-health officials have been so

insistent on painting sunshine as the enemy that they can't stand to hear

about the substantial benefits of sunlight, including promoting strong bones

and easing depression.

" It's easier for them to say just don't be exposed to sunlight instead of

providing the thoughtful, intelligent recommendation that maybe a little sun

is good for you, " says Holick.

" I am not advocating a return to the baby-oil and sun-reflector tanning days

of the past, " he points out. " This is about spending a few minutes in

natural or artificial sunlight several times a weekwithout sunscreento

satisfy your body's vitamin requirement. It is not about damaging the skin. "

AAD adamant about avoiding the sun

The AAD says Holick is " irresponsible " and likens his advice on going

unprotected into the sun for health benefits to suggesting " smoking to

combat anxiety. " The academy emphasizes the risk of skin damage and skin

cancer, reiterating its message at a recent news briefing to launch its

Melanoma/Skin Cancer Detection and Prevention Month.

Speaking at the event, dermatologist Rigel pointed out that the US

Department of Health and Human Services has declared UV radiation as a known

carcinogen. One American dies every hour from melanoma, the most serious

form of skin cancer, he points out. " The fact is, skin cancer is increasing

at an alarming rate, and scientific research confirms that our best defense

is avoiding excessive, unprotected sun exposure. "

" Until there is science that tells us otherwise, it is imperative that

people protect themselves from the sun. Anyone concerned about not getting

enough vitamin D should either take a multivitamin or drink a few glasses of

vitamin-D-fortified milk every day, " he commented. " Normal vitamin-D levels

are easily maintained through routine daily activities (even when wearing

sunscreen) and a normal diet, " he maintains, " so supplemental vitamin-D

tablets are typically not needed. "

Holick strongly disagrees. " It is improper for unenlightened dermatologists,

many of whom know little about human nutrition, to suggest that consumers

can get all their vitamin D from diet. It would require drinking 10 glasses

of milk or fortified orange juice every day. "

" The literature is clear. Adequate amounts of vitamin D cannot be achieved

at the current low levels set years ago by the Institute of Medicine200 IU a

day, " Holick says. " Consumers should routinely be taking 5 times that

amount, 1000 IU a day of vitamin D. It is misleading to suggest that

nutritional supplementation is the answer. It is not practical to get our

daily 1000 IU of vitamin D from popping a pill. More important, supplements

do not provide the same benefits as sunshine, and if taken in too large a

dose, they can cause vitamin-D toxicity. "

Epidemic of vitamin-D deficiency

" Today we face what is, in fact, a 'medically significant' epidemic of

vitamin-D-deficient people, " Holick says. Between 40% and 60% of Americans

are seasonally or chronically vitamin-D deficient, he claims.

Other experts have also voiced concerns about vitamin-D deficiency. Late

last year the issue was discussed at a conference organized by the US

National Institutes of Health to assess the " alarming prevalence of low

circulating levels of vitamin D in the US population. " The meeting heard

speculation that low levels of the vitamin could be due to a lower intake of

vitamin-fortified foods, particularly milk and cereal; an increase in the

use of sun block and decreased sun exposure; and an increase in the

popularity of breast-feeding.

Even Gilchrest acknowledges that many people are vitamin-D deficient, but

she says the risk is very small compared with the danger of melanoma, which

is expected to strike 55 000 Americans this year. She says vitamin-D

deficiency is " hardly an epidemic. What I see every single week is people

with skin cancer. "

" Consumers should be knowledgeable about the potential risk of skin cancer, "

Holick concurs, but he points out that " fewer than 0.5% of those who develop

nonmelanoma skin cancer die, about 1200 people a year in the US. "

In contrast, " mortality rates indicate that 150 000 people die of diseases

that can be prevented by sensible sun exposure, " he says.

Zosia Chustecka

Source

1. Holick M. The UV Advantage. : I Books; May 2004.