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Saturday, January 31, 2009

Perspective on Vitamin D

I have written a number of articles about vitamin D and health. I have some concerns that for the most part have probably not been considered, but then I am not one that works off of linear thinking models.

There are a variety of opinions on vitamin D, including one that is fairly negative. However, in good science, the best outcomes are achieved if we are open minded enough to look at all possible vectors.

I agree that vitamin D is an important nutrient. I agree that it appears clear that we are experiencing a problem with low levels of vitamin D in most people.

People of color require more. People who do not go out in the sun need more. And people who exclude healthy fats from their diet, such as the philosophy of no fat promulgated on the public over the past several decades, really do need more.

Just look at the rates of osteoporosis and other calcium related health problems for starters.

Look at the history of health as it relates to sun exposure that was established as long ago as 2500 BC.

There must be something to the practice of exposing your skin to the sun, free of sunscreens that contain endocrine disruptors. Sunlight entering your eyes for a short periods of time each day also is known to be part of the vitamin D-calcium-parathyroid interplay.

If I relied on food for vitamin D I would have to look to
Concentrated food sources of vitamin D include salmon, sardines, shrimp, milk, cod, and eggs.

Sockeye salmon are an exceptionally rich source of vitamin D: a 4-ounce serving of baked or broiled sockeye salmon provides 739.37 IU of vitamin D. The same 4-ounce serving of chinook salmon, another excellent source of vitamin D, supplies 411 IU.

Why are sockeye salmon even more richly endowed with vitamin D than other salmon species? Because zooplankton constitute so much of their diet, and zooplankton-along with phytoplankton-are the key sources of vitamin D in the marine food chain. The zooplankton eaten by salmon are tiny marine animals, such as larval-stage crustaceans, while the phytoplankton eaten by salmon are small, plant-like marine organisms.

Both types of minuscule sea life create lots of vitamin D from sunlight, and zooplankton feed on phytoplankton, building up their vitamin D content to even higher levels. Unlike most other fish and salmon species (except chum), sockeye feed largely on zooplankton through all stages of life. Chinook, on the other hand, feast on insects and sideswimmers when young, then consume a variety of fish, especially smelt and ciscoes, a type of lake herring, as they mature. from WH Foods

This might be boring, and if I selected milk I would more likely begetting the synthetic form of vitamin D.

There just is much more to this than relying on supplements and staying out of the sun for fear you will get skin cancer. For my money I'll support Holick.

Also remember that vitamin B1 and a spray of vitamin C make good sunscreens without all the chemicals that might be more harmful in the long run that 15 or 20 minutes of exposure to sunlight, outside of the hottest hours of the day.

Michael Holick's experience also sheds some light on just how lineal and intellectually limiting most ivory towered institutions of "higher learning" really happen to be.
Five years after being fired from one post, sun exposure proponent keeps up the fight

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 BU, 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 New England Journal Medicine, almost exactly five years after he left BU’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, 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 Academy 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, ten or 15 minutes, don't be paranoid."

Other opinions:
Major Lab Discloses Problem With Vitamin D Testing

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