NEW RESEARCH
A study from Harvard Medical School shows an increased risk of heart disease for those with low levels of vitamin D, and this risk is particularly high for those who also have high blood pressure.
- The U.S. study, which began in 1996, used over 1,700 people with an average age of 59.
- Those with low levels of vitamin D in their blood, below 15 nanograms per millilitre (ng/ml), had twice the risk of a heart attack, heart failure or a stroke compared to those with higher levels (above 15ng/ml).
- The highest incidence of cardiovascular disease was seen in those with high blood pressure and low vitamin D levels.
- The researchers say that because receptors for vitamin D are found in heart muscle and blood vessel lining, low levels could be a contributing factor in heart disease.
HOW IT WORKS
1. SUN
The sun is the principle source of vitamin D
2. SKIN
The sun’s energy is used by the skin to produce cholecalciferol, a form of vitamin D known as D3.
3. LIVER
Once vitamin D is produced in the skin or consumed in food, it requires chemical conversion in the liver and kidney to form 1,25 dihydroxyvitamin D, the physiologically active form of vitamin D.
4. KIDNEYS
Vitamin D is absorbed by the kidneys,
maintaining calcium balance in the body
5. FOOD
Vitamin D is found naturally in oily fish such as salmon, tuna and sardines. It is also added to milk, soy beverages and margarine.
GROUPS AT RISK OF VITAMIN D DEFICIENCY
- The elderly
- Exclusively breast-fed babies
- Individuals with dark skin
- Individuals with limited sun exposure
- Those who during the winter are living above 37 degrees latitude (Canada and northern U.S.)
Selected food sources of vitamin D
Cod liver oil, 1 Tbsp - 1,360 Intl. Units (IU) per serving
Salmon, cooked, 3 ounces - 360 IU
Mackerel, cooked, 3 ounces - 345 IU
Tuna fish, canned in oil, 3 ounces - 200 IU
Sardines, canned in oil, 1 ounces - 250 IU
Milk, fortified, 1 cup - 98 IU
Margarine, fortified, 1 Tbsp - 60 IU
Ready-to-eat cereals, fortified, 1 cup - 40 IU
Egg, 1 whole - 20 IU
Liver, beef, cooked, 3 ounces - 15 IU
BENEFITS of Vitamin D
- Heart disease: Vitamin D deficiency may increase the risk of heart attacks and stroke.
- Cancer: Vitamin D may reduce the risk of some forms of cancer including prostate, pancreatic, colorectal, and breast cancer.
- Strong bones: Aids in growth of strong bones, which protect against osteoporosis in old age.
- Multiple sclerosis: Low levels of vitamin D may present a higher risk of multiple sclerosis.
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IN THE NEWS
BLUE EYES RELATED
Single, common ancestor
University of Copenhagen research shows people with blue eyes have a lone, common ancestor. The research team has tracked down a genetic mutation which took place 6,000 to 10,000 years ago and is the cause of the eye colour of all blue-eyed humans alive on the planet today. “Originally, we all had brown eyes,” said professor Hans Eiberg from the Department of Cellular and Molecular Medicine.
DARK DISCOVERY
Now this is pitch black
Researchers at Rensselaer Polytechnic Institute and Rice University have created the darkest material ever made by man. The material, a thin coating comprised of low-density arrays of loosely vertically aligned carbon nanotubes, absorbs more than 99.9% of light and one day could be used to boost the effectiveness and efficiency of solar energy conversion, infrared sensors, and other devices. The researchers have applied for a Guinness World Record for their efforts.
GIRL POWER
Female fish decide who moves up
Aggression, testosterone and nepotism don’t necessarily help one climb the social ladder, but the support of a good female can, according to new research on the social habits of an unusual African species of fish. McMaster University researchers came to the conclusion after studying how males respond to changes in social position in the cichlid fish off the Zambian shores of Lake Tanganyika in Africa. “We found that changes in social status were regulated by the most dominant female in a social group”, said lead researcher John Fitzpatrick. “In fact, dominant females seemed to act as gatekeepers, allowing only males larger than themselves to move up in status and become dominant.”
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