The Importance of Vitamin D

What is vitamin D? Originally credited with helping the body with calcium and bone metabolism, more recent studies show that vitamin D has many other influences on keeping the body healthy. It is thought of as a prohormone more than just a vitamin because it is only after D3 is metabolized in the liver and then into other forms in the kidneys that the active forms are produced. To date, some thirty-seven forms of Vitamin D3 have been isolated and chemically characterized.

Since we make vitamin D from exposure to the sun, it is almost impossible for the average Canadian to maintain optimal vitamin D levels from sunshine alone, especially from October through March. A person’s ability to make the vitamin is influenced by many factors, including age, weight and skin pigmentation. People also need a certain amount of dietary fat as well as cholesterol in order to make adequate vitamin D. This means people suffering from Crohn’s disease, cystic fibrosis or liver disease, on low fat diets, or on cholesterol lowering medications often have low vitamin D levels.

Do we have enough? Statistics Canada released a survey in March of 2010 stating that 2 out of 3 Canadians have less vitamin D than considered necessary for optimal health. About ten percent of Canadians fall below the minimum needed for good bone health. Men were more likely than women to have inadequate levels of vitamin D in their blood — especially between the ages of 20 and 39.

This is staggering news considering that vitamin D is involved in maintaining optimal cellular, digestive, cardiovascular, immunological, musculoskeletal and neurological health (basically, all of your body systems). Low levels of vitamin D is definitely linked to the incidence of all types of cancer, autoimmune disease and mood disorders, just to name a few.

For lighter skinned people, you need at least twenty minutes of exposure to direct sunlight every day to produce the vitamin D you need – that means no windows, no clothing, no sunblock.

Some interesting things to note:

  • all cells and tissues in your body have vitamin D receptors — and further concludes that every cell and tissue needs vitamin D for its well-being
  • vitamin D is responsible for the regulation of over 2,000 genes in your body (out of a total of 30,000)
  • a recent study in Science shows that vitamin D may be a potent antibiotic by increasing the body’s natural production of antimicrobial peptides (I do use it in high doses for flu and colds – 10 000 IU/day for 2-3 days)

Promising research:

  • American Journal of Clinical Nutrition, published in June 2007 cited a 60 to 77 per cent decrease in cancer rates in postmenopausal women who took a daily dose of 1,100 IU of vitamin D combined with calcium over women who were given a placebo or calcium alone.
  • American Journal of Preventive Medicine revealed in the March 2007 issue that taking 2,000 IU of vitamin D daily along with 10 to 15 minutes in the sun and a healthy diet could reduce the incidence of colorectal cancer by two-thirds. The same authors found that breast cancer rates were 50 per cent lower in people with high levels of vitamin D in their blood, and suggested that the average person could maintain those levels by taking 2,000 IU of vitamin D daily and spending 10 to 15 minutes in the sun.
  • A December 2006 study of more than seven million Caucasian people in the U.S. Military with high serum vitamin D were 62 per cent less likely to develop multiple sclerosis than those with the lowest levels of the vitamin.
  • Archives of Internal Medicine published on May 28, 2007 women who consume higher amounts of calcium and vitamin D may have a lower risk of developing breast cancer before menopause. The study followed more than 31,000 women aged 45 and older for 10 years. It found that intake of calcium and vitamin D was moderately associated with a lower risk of breast cancer before — but not after — menopause.

What is the best way to get vitamin D? Ideally, we could all go outside year round and make vitamin D naturally. Our bodies are well equipped to know when enough is enough, and when we make it naturally, it is impossible to get too much. Unfortunately, this option is impractical for Canadians, where the amount and angle of sunlight is inadequate for a minimum of six months of the year.

There are safe tanning beds available that are designed to help vitamin D production without the harm of a conventional tanning bed. Since UVB rays are the wavelength used by the skin to produce vitamin D, these systems optimize exposure to this wavelength. There are systems available on the market ranging from $1500 to $3000 USD.

More commonly, people are choosing to supplement vitamin D. Vitamin D is oil soluble, which means it accumulates in your system (unlike water soluble vitamins like B complex and C). Two things to bear in mind when supplementing – firstly, choose vitamin D3 over synthetic vitamin D2, as it is the naturally occurring form. Secondly, you need to have your blood levels regularly checked to ensure that you are not overdoing it. The reality is however, that vast majority of us, as the recent Statistics Canada report shows, are deficient in this precious vitamin, not in excess.

In fact, one theory as to why we get “colds” in September & October is that as the weather gets colder, we go inside and make less of our own vitamin D for our immune function. Make sure you get enough this year to keep your immune system, and the rest of your body strong.

Tasleem Kassam