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Jan 30, 2009 07:17 PM | 18
If the name Michael Holick means anything to you, you will recall that he was asked to resign from a post in Boston University’s dermatology department in February 2004 for promoting “sensible sun exposure” in his book The UV Advantage.
Holick’s thesis—which was apparently anathema to Boston University derm department chair Barbara Gilchrest—is that most people who live in the US north of Atlanta are vitamin D deficient because one of the key sources of that vitamin is the sun. (Vitamin D is essential for the absorption of calcium and thus strong, healthy bones.) And even when the sun shines brightest, and for the longest, during the summer, we’re told to shun the sun and slather our bodies in high SPF sunscreens to defend against skin cancer.
But in doing so we might be hiking our risk for a variety of health problems including heart disease, breast cancer, and colon cancer, says Holick. "You have about a 30 to 50 percent decreased risk of developing colon, prostate, and breast cancer if you maintain adequate vitamin D levels throughout your life," Holick said in a 2007 interview with a Canadian television station.
In case you were wondering what happened to him, Holick was unbowed by his firing. (He is still at B.U., holding down a professorship in medicine, physiology and biophysics). He has kept up his advocacy of sunlight exposure, so perhaps we shouldn’t have been surprised to see a report of rickets—a disease in which the bones become softened or weakened due to vitamin D deficiency—he diagnosed in last week’s The New England Journal Medicine, almost exactly five years after he left B.U.’s dermatology department.
The report is of a mysterious case: A nine-month-old baby boy admitted to Mass General with violent seizures. A battery of tests revealed that the boy had abnormally low levels of calcium in his blood, which is known to cause seizures. A blood test then revealed Holick’s specialty: Vitamin D deficiency, which causes rickets.
The vitamin D and calcium deficiencies are related, Holick told us this week. Without enough vitamin D, the body can't absorb calcium properly. Holick says that vitamin D deficiency is very common in American babies and mothers. One of his studies looking at vitamin D levels in 40 mother-baby pairs found that 76 percent of moms and 81 percent of babies are deficient, meaning they had less than 20 nanograms per milliliter of blood. (A nanogram is one billionth of a gram).
To prevent such deficiency, Holick says pregnant women, and all adults for that matter, should be taking at least 1000 units of the sunshine vitamin a day. That means taking vitamin supplements in addition to a normal multivitamin, which typically contains only 400 units. But be advised, you can overdose on vitamin D: Taking 50,000 units per day for a long period of time can be toxic. (Holick wrote a case report about it.)
The American Academy of Dermatology (AAD), however, only recommends that kids and adults get at least 200 units of vitamin D per day either from the food or the sun. Holick says the academy's recommendations pretty much ignore research that suggests that these levels put a person at risk for heart disease, infections and various types of cancer. "They continue to have blinders on," Holick says.
A cynic might say those blinders are because the academy fears the sun. The AAD says that people should get vitamin D from a healthy diet incorporating foods naturally rich in or fortified with it, such as milk and orange juice, and/or vitamin D supplements—but not through unprotected sun exposure, which is linked to skin cancer.
"The recommendation that you should never be exposed to the sun is putting many people at risk for vitamin D deficiency," Holick says. While in the sun, it's important to cover the face but okay to expose the arms and legs for 10 minutes or so without sunscreen, he adds. "If you're going to be out in the sun for five, 10 or 15 minutes, don't be paranoid."
Image credit/NASA
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18 Comments
Add CommentSeems like a rational idea to me. I can understand that our skin is damaged by UV radiation but we have been living under the sun for a long time and should not be afraid of prudent sun exposure. We should not have to slather bodies with chemical agents to protect us if we want to enjoy a nice meal in the mid morning sun enjoying our surroundings. I'd much rather get a nutrient from its more natural source than thru any supplements when easily obtainable.
Reply | Report Abuse | Link to thisThis sounds more like a clash of egos than a scientific debate. Some straightforward epidemiological data on Vitamin D deficiency vs skin cancer vs sun exposure would enable sensible balancing of risks. It seems simplistic to put sun exposure in the same class as cigarette smoking when millions of people work and play outdoors and the incidence of melanoma is hardly epidemic. A zero-risk life based on pills and ointments is neither practical for most people nor a very satisfying one.
Reply | Report Abuse | Link to thisTaking vitamin D supplements is very sensible. I take 2000 IU/day, which is the max recommended amount without having blood tests to monitor vitamin D level. You can keep vit. D levels high even in the winter that way, and help prevent breast cancer etc.
Reply | Report Abuse | Link to thisHolick's book was strange in promoting unprotected sun exposure, which ages the skin and causes cancer, over a very inexpensive supplement. I've heard he has some connections to the tanning industry.
larkalt: Connection to tanning would encourage usage of artificial sun tan or the use of suncream.. those are tanning industry source of income, not unprotected sun exposure.......
Reply | Report Abuse | Link to thisIf you want some very good and up to date information regarding vitamin d (which is not really a vitamin but a steroid hormone) go to http://www.vitamindcouncil.org or http://www.grassrootshealth.org
Reply | Report Abuse | Link to thisAn abundance of information at these links and both are not-profits. The dermatological society has been bought and paid for by the sunscreen industry. They've turned us all into vampires.
Regardless of your beliefs, evolution or creationism.....why would we evolve in an environment that is so bad for us? Why would your higher power put you someplace that will harm you?
Do the Science people. Humans in latitudes nearer the equator have less incidences of autism, MS, most autoimmune diseases, most cancers, and they actually live longer.
I would just like to point out that while sun exposure is obviously linked to skin cancer, it's been known for some time now that the oxybenzone in sunscreen is also carcinogenic. Since you are at risk for skin cancer either way, you might as well reap the Vitamin D benefits of sun exposure.
Reply | Report Abuse | Link to thisAs hunter gatherers we spent a lot more time in the sun. We need to get closer to what was natural to us. Slather sun screens which are absorbed by our bodies increases the toxins in our bodies. Isn't it true that we should not apply on our skin anything that we would not eat?
Reply | Report Abuse | Link to thisLuckily, there is now a user friendly 'blood spot' test available from GrassrootsHealth.org for $30 (click on the D-Action button). No invasive venous blood draw, just tap the lancet and it pricks the finger (or baby's heel); then let some drops of blood fall into circles on the blotter paper and send it in. It hurts no more than plucking an eyebrow hair.
Reply | Report Abuse | Link to thisAs a teacher, I am concerned at the negligence of public health officials regarding the national D deficiency. Growing children need D and all the recent research says food won't provide enough.
Parents no longer insist their kids swallow that 'lovin' spoonful' of cod liver oil each morning. They need to know there is a less tortuous way to insure their kids get enough: D3 from lanolin has no fishy taste and is usually a powder that can be mixed into a dab of apple sauce. Schools should notify parents of the D deficiency epidemic and explain how to get a test and how to provide supplements.
(Of course, cod liver oil provides omega-3s as well, which school food also neglects, but that's a separate issue which can be resolved by chewable supplements or sardines---which are low on the food chain and therefore better than tuna regarding mercury residue.)
The Achievement Gap is that difference between the higher test scores Asian and white students and the lower scores of black and Latino students. This gap has mystified educators and resisted years of new curricula and extra teacher training. Maybe the gap is based on physiology rather than culture--namely that students with more melanin can't make as much vitamin D in their skin, and therefore are more D deficient.
Since nearly every cell has D receptors, including brain cells, D deficiency may impact school achievement more than is generally recognized.
Making Americans D 'replete' would be one of the easiest, fastest, cheapest fixes in the history of public health. A one-size-fits-all RDA is ridiculous because there are too many variables for each person (skin color, weight, age, sun exposure, fish consumption, etc.).
Once a person's 25-OH-D level is known, supplementation can be tailored to need. NRP reported on Boston's Mattapan Community Health Center, where some patients are prescribed 7000 IU a day.
Visit goodschoolfood.org for more info on vitamin D (top item in left margin).
j.quasimodo: Skin cancer is indeed considered an epidemic by most researchers and physicians. The rates for basal cell carcinoma, squamous cell carcinoma and melanoma are all increasing, by as much as 2-3% per year. Skin cancer is one of the few types of cancer that is increasing. This continued increase is directly due to excessive sun/UV exposure. You can get your daily dose of vitamin D in less than 15 minutes in the sun or eating well and taking a supplement. This article is clearly biased -- be careful!
Reply | Report Abuse | Link to thisi heard that in the us, some people live their lives travelling in an airconditioned car between the aircon'd office, the aircon'd mall, and the aircon'd home. people, when we talk about the health risks of 10...15minutes of unscreened sun exposure anywhere in the us at any time of the year, we should realize we could get the most significant health benefits by skipping this topic immediately and move on to discussing PARANOIA. seriously.
Reply | Report Abuse | Link to thisdiscipline, it's completely possible that such an increase in skin cancer is a function of insufficient <b>measured</b> exposure through human development. If the body is not brought up with judicious exposure and kids are constantly covered or indoors, it's reasonable to speculate that the resultant adult will be at a disadvantage when accidently overexposed. As the industry sells us more sunscreen, it's actually more reasonable that increased skin cancer should correlate with that variable or decreased measured exposure. None of my cohorts were ever slathered nearly to the degree that my friends slather their kids. I'd be more convinced by your skepticism if cancer rates had gone down. I'm not saying that Holick is categorically right, but if cancer rates are increasing we should look at what has changed in like proportion. It seems that his point is a reasonable one to be considered in the face of an industry’s profit motive, whether screen or pill.
Reply | Report Abuse | Link to thisdiscipline, it's completely possible that such an increase in skin cancer is a function of insufficient <b>measured</b> exposure through human development. If the body is not brought up with judicious exposure and kids are constantly covered or indoors, it's reasonable to speculate that the resultant adult will be at a disadvantage when accidently overexposed. As the industry sells us more sunscreen, it's actually more reasonable that increased skin cancer should correlate with that variable or decreased measured exposure. None of my cohorts were ever slathered nearly to the degree that my friends slather their kids. I'd be more convinced by your skepticism if cancer rates had gone down. I'm not saying that Holick is categorically right, but if cancer rates are increasing we should look at what has changed in like proportion. It seems that his point is a reasonable one to be considered in the face of an industry’s profit motive, whether screen or pill.
Reply | Report Abuse | Link to thisBarbara Gilchrest's decision represents a major pitfall of 'science'. That a logstanding departmental bias would prevail despite documentation to differ from that bias is unconscionable and anti-science. If the research held up to scrutiny it should have been Gilchrest who was asked to leave. Thwarting attempts at scientific progress is no better than the church vs. Galileo.
Reply | Report Abuse | Link to thisIf the science panned out, it should have been Gilchrest being asked to leave her post. There is no room in science, despite it's prevalence, for bias overriding new findings. That it occurs is unconscionable. This is tantamount to the church's threatening Galileo.
Reply | Report Abuse | Link to thisCommon sense, please, people. A moderate amount of sunshine in the morning or late afternoon, with most of the time in the shade would seem to be a prudent practice. Based on recent research, unless you are taking cod liver oil (like my mom used to make us do) you should probably be taking a Vitamin D supplement, especially if you live in northern latitudes. Now, go out and play nice.
Reply | Report Abuse | Link to thisSince it is virtually impossible to get enough vitamin D from the diet, supplementation is definitely necessary in the winter. However, cod liver oil is not the answer. The problem? Cod liver oil contains excessive amounts of vitamin A.
Reply | Report Abuse | Link to thisThe vitamin A to vitamin D ratio (in IUs) is 10:1 or more. If you were to take enough cod liver oil to get, say, 2,000 IU per day, you'd end up with at least 20,000 IU of vitamin A, or twice the tolerable upper intake level (UL) set by the Food and Nutrition Board of the U.S. Institute of Medicine.
Not only would you risk getting potentially toxic levels of vitamin A, but the high vitamin A content actually cancels the effect of the vitamin D in cod liver oil. Put differently, its vitamin A content defeats the purpose of taking cod liver oil for its vitamin D.
Source: Cannell JJ et al. Cod liver oil, vitamin A toxicity, frequent respiratory infections, and the vitamin D deficiency epidemic. Ann Otol Rhinol Laryngol 2008;117:864-870.
When we grew up we all played outdoors all the time, often with as little clothing as possible. Even while very young I learned to increase gradually to avoid sunburn which I maintain is the prelude to skin cancer later. Complexion obviously must be considered.
Reply | Report Abuse | Link to thisToday's kids never get out of the house! They are too supervised, entertained, cared-for and protected; consequently they are ill equipped to deal responsibly with adult decisions when they're called upon.
Their skin cancer risk is nothing compared to the life skills they lack. Kick their butts outside, tell 'em to be home at suppertime.
One immediate concern jumped to my mind, regardless of Dr. Holick's expertise or lack thereof: Rickets can be a side effect of a fairly rare genetic condition, cystinosis.
Reply | Report Abuse | Link to thisAbout 30 years ago my niece was diagnosed with it. She was less than two years old at the time. The "breakthrough" was that she was seen by an older doctor who had personally observed kids/infants with rickets during his career.
In her case the vitamin D deficiency was a side effect, I just hope kidlets these days get a quicker/easier diagnosis.