Canada & Vitamin D Deficiencies

Exposure to as little as 10 minutes of midday sunlight is critical for getting your daily dose of vitamin D, especially if you live in Canada. About 97 percent of Canadians have deficient levels of vitamin D at some point during the winter or spring months, Gerry Schwalfenberg reports in "Canadian Family Physician." While a number of risk factors, including geography, skin pigmentation and diet, play a role, a growing body of scientific evidence suggests vitamin D deficiency is linked to various diseases and health conditions.

About Vitamin D

Vitamin D is a fat-soluble vitamin that helps your body absorb calcium and phosphorus for building and maintaining bones and teeth. Vitamin D is found naturally in foods, including egg yolk, fish such as mackerel and salmon, fortified milk, and cod and halibut liver oils. Your body also produces vitamin D when your skin is exposed to sunlight, which triggers synthesis of the vitamin.

Risks of Deficiency

Canadians who live at latitudes 43 to 55 degrees north are at high risk of suffering from vitamin D deficiency. Here, four to five months of the year, UVB sunlight is too weak to synthesize enough of the vitamin. When vitamin D levels are insufficient, blood calcium and phosphorus levels drop, forcing your body to pull calcium from your bones. This may cause a softening or weakening of bones, known as rickets in children and osteomalacia in adults. Scientific studies also link vitamin D deficiency to muscle weakness and pain, an increased risk of fractures, Type 1 and Type 2 diabetes, multiple sclerosis, rheumatoid arthritis, psoriasis, heart disease, certain types of cancer, obesity and high blood pressure.

Recommended Intake

Health Canada recommends Canadians ages 9 to 70 get 600 international units, or IU, of vitamin D per day; adults 70 and older, 800 IU; and pregnant and lactating women, 600 IU daily. The government agency also recommends a daily vitamin D supplement of 400 IU for anyone over 50 and for healthy term, breastfed babies. However, some research suggests these recommended levels might be too low, especially for certain health conditions. Talk to your doctor about the right dose for you.

Deficiency in Canadians

An estimated 1.1 million or 4 percent of Canadians ages 6 to 79 are vitamin D deficient, according to study by Kellie Langlois and colleagues in the March 2010 edition of the journal "Health Reports." The researchers found men were less likely to have adequate levels of vitamin D than women, especially men from 20 to 39 years old. About 7 percent of men ages 20 to 39 were vitamin D deficient, the highest percentage among all age groups. The researchers suggest low milk consumption among adults, reduced exposure to sunlight during winter months and skin pigmentation may account for vitamin D deficiency among Canadians. People with darker skin need four times as much sun as those with light skin to get the same dose of vitamin D, Schwalfenberg notes.

Premature Deaths and Economic Burden

The death rate from diseases related to vitamin D and the associated economic impact would decline by 16.1 and 6.9 percent, respectively, if Canadians had higher levels of the vitamin, according to William B. Grant and colleagues in an August 2010 edition of the journal "Molecular Nutrition and Food Research." The researchers note about 37,000 deaths could be prevented and $14.4 billion saved in health care costs if half the Canadian population had above-recommended levels of vitamin D.