Researchers from the University of Toronto have found all subjects of African origin to be short on vitamin D. Over 80 percent of South Asians and East Asians were also low on "the sunshine vitamin".
In this study, the researchers conducted blood tests on 107 students during the less sunny months of February and March. The cutoff for insufficient blood levels of vitamin D was 50 nanomoles/litre - roughly half the amount found to prevent cancer in a U.S. study earlier this year.
The students completed a 7-day food record to determine how much vitamin D they were getting from their diet.
One hundred percent of students of African origin had insufficient blood levels of vitamin D. Only seven percent of students from South Asia and 15 percent of students from East Asia had enough vitamin D in their blood.
Students of European descent were far less likely to have low blood levels of vitamin D. Of the Europeans surveyed, 34 percent didn't meet the designated cutoff.
These findings, which are awaiting publication in a medical journal, may have drastic implications for public health officials given Canada's growing non-white population.
Canada's strategy for increasing vitamin D intake has been to fortify dairy food with this important nutrient. However, many non-whites don't obtain the 1,000 IU of vitamin D a day recommended by the Canadian Cancer Society.
A key source of vitamin D comes from a person's skin, which naturally produces this nutrient when exposed to UV light. People of non-white origin appear to have slower production of vitamin D due to more melanin in their skin, which acts as a "natural sunscreen".
Food sources of vitamin D include fatty fish - sardines, salmon, tuna, mackerel, cod and herring - fortified milk and milk beverages, eggs, butter and margarine. One cup of lower fat milk (250 ml) provides 100 IU of vitamin D.
Health Canada recommends 200-600 IU of vitamin D each day depending on your age, race, and exposure to sunlight.
Supplements can provide between 400 and 1,000 IU of vitamin D per dose. We recommend you speak to a registered dietitian before starting a supplement regime.
All research on this web site is the property of Leslie Beck Nutrition Consulting Inc. and is protected by copyright. Keep in mind that research on these matters continues daily and is subject to change. The information presented is not intended as a substitute for medical treatment. It is intended to provide ongoing support of your healthy lifestyle practices.