The Healing Vitamin

Samar Elhamalawy didn’t know what was wrong with her little son. But when Mahmood was nine months old, he suddenly lost interest in walking. He reverted back to crawling, from standing and cruising along the couch. ” He just started to deteriorate,” the Hamilton mother of two recalls. A few months later, she worriedly asked her family doctor why he had so few teeth. Then, at 14 months old, the little boy took two steps, fell down and broke his arm.

Within a month, Hamilton bone specialists diagnosed Mahmood with rickets, a bone-weakening disease caused by vitamin D deficiency.

Looking back a century, the slums of New York and London teemed with children whose weak, spindly limbs and bowed legs testified to their D deficiency. The disease all but disappeared after the 1920’s, when doctors realized it could be cured by sun exposure.

But lately the malady has been making a comeback. That’s bad news, and not just for kids: Nowadays scientists are linking low levels of D to cancer, hypertension, diabetes, multiple sclerosis, osteoporosis and inflammatory bowel disease.

More and more evidence is mounting that vitamin D plays an absolutely pivotal role in all aspects of human health.

Researchers used to think D’s main value was in building strong bones. But new research shows that this humble nutrient is far more versatile. Unlike other vitamins, D isn’t found in much we eat. Instead, most is supplied by the sun. The process begins when a molecule in the skin called 7-Dehydrocholesterol reacts to ultraviolet light and turns into vitamin D. It then travels to the liver, where it picks up extra molecules of oxygen and hydrogen. This process transforms the skin molecule into a potent pre-hormone called calcidiol. Scientists now think many tissues in the body’not just the liver can convert the calcidiol to make their own calcitriol, the active disease-fighting compound of vitamin D.

Let the sun bake your unprotected arms and face for a few minutes a day and you’ll make all the D you need—it sounds simple. But combine Canada’s short summers, indoor lifestyle, sun-blocking pollution and the fact that even sunscreen with an SPF of 8 reduces D absorption to virtually nil, and many of us end up falling short. While you can get some D in the spring and fall, summer in Canada is the best time to stock up (your body can store D for several months). Forget about winter. From early October until late March, the ultraviolet light you get in a city is not enough to generate vitamin D.

The vitamin is absorbed through the skin, and people with darker skin types tend to be more deficient. Meanwhile, the elderly tend to be at higher risk for D deficiency because they tend to avoid sunshine.

One result of the growing D deficiency is more and more rickets cases each year. ” Mahmood was born in January and wasn’t exposed to a lot of sunlight,” says his mother, Samar. His dark skin probably didn’t help. But after a month on vitamin therapy, the little boy bounced back and started walking. By 22 months of age, seven months after starting treatment, tests showed no trace of bone problems.

What really worries D experts, though, is what Mahmood’s deficiency may represent: huge chunks of the world’s population living with a chronic lack of D, which boosts the risk of serious illnesses. At the top of the list?

Cancer
The cancer theory got its legs in 1980 after Frank and Cedric Garland, epidemiologists and brothers, were struck by maps showing that the rate of colon cancer was about twice as high in the cloudy northeast United States as in the south. People who consumed the most vitamin D or had the highest levels of Din their blood had a lower risk of colon cancer. ” We know sunnier places have lower breast-cancer rates compared with more northern countries.”

A teacher in the School of Medicine in North Carolina has studied the role of D in prostate cancer. Prostate cells, he has shown, produce the hormone calcitriol, which can act as a brake on cell growth. When the cells can’t get enough calcidiol to make calcitriol, it’s as if the brake lines are cut, he reasons. The cells can multiply uncontrollably, and cancer results.

Diabetes
People in Finland, where the sun shows its face for only a few hours a day during winter, have the world’s highest incidence of Type 1 diabetes. But vitamin D reduces their risk for the disease. In one study tracking 10,000 children, researchers found that those who got regular doses of vitamin D as infants were about 80 percent less likely to later develop Type 1 diabetes than those who did not get enough. So the vitamin may help by preventing destruction of the cells that produce insulin.

Hypertension
It’s long been known that a population’s average blood pressure rises the farther the country is from the equator. A doctor recruited 18 volunteers with mild hypertension and put them under ultraviolet lights for at least six minutes, three times a week. After six weeks, the amount of D in their systems had more than doubled and their blood pressure had dropped significantly to normal for some. The lights may work, says this doctor, because they boost calcitriol production by the kidneys, and calcitriol tamps down enzymes that cause blood vessels to constrict, a major cause of high blood pressure.

Osteoporosis
In the intricate ballet of calcium regulation that goes on in our bodies, when D goes missing, another hormone, parathyroid hormone, builds up and starts pulling calcium out of the skeleton.

One result is the bone-brittling disease osteoporosis. If people don’t get the right balance of both calcium and D throughout their lives to help build up bone strength, their bones can weaken and easily fracture in their senior years.

We need calcium because we’re really deprived of vitamin D. If we had enough D, we wouldn’t need so much calcium.

Eventually, prevention of osteoporosis ‘which should start in childhood’ may involve people taking vitamin D supplements and basking in the sun.

Multiple Sclerosis
Getting lots of vitamin D from sun exposure might also reduce your risk of developing multiple sclerosis, a degenerative neurological disease. One Australian study found that people who had more sun exposure as children were much less likely to develop the disease. It’s been suggested that taking high doses of D might both prevent the disease and aid in its treatment.

Inflammatory Bowel Disease
Crohn’s disease and ulcerative colitis ‘both which fall under the category inflammatory bowel disease (IBD)’ are both more common in northern nations and are associated with vitamin D deficiency.

How Much D?
The dangers of not getting enough vitamin D are so great that experts say people should take a blood test for D levels once a year – just as they check their cholesterol regularly. Your doctor can order this test for you at any time.

Current Health Canada recommendations for vitamin D suggest people under 50 get 200 international units (IU) a day; people age 51 to 70 should get 400 IU a day; and those over 70 should aim for 600 IU. But experts don’t think that’s enough. In a study of young Canadian women, it was found that those who took 400 IU a day had the same deficiency rate as those who didn’t. These women were taking double what the government said they should and it had zero consequence on their blood-vitamin D levels.

Studies suggest it takes about 800 IU daily to impact bones, but top experts recommend buying a 1,000 IU supplement to get real health benefits. (It is possible to get a toxic buildup of calcium in the bloodstream, but only if you take megadoses of vitamin D. some recommendations suggest that 4,000 IU a day could be toxic. However, the new data experts have collected suggest you’d have to take 40,000 IU a day for long stretches for the vitamin to be dangerous.
You can also combine a supplement with getting D elsewhere. Look for D-fortified brands of soy beverages. Better still, soak up the rays on warm, sunny days or when you’re on a winter vacation. Fill up your vitamin D bank with ten minutes a day without sunscreen.