What's the deal with vitamin D?

by dietitians, Erin Croke, PDt. & Laura Kingston, PDt.

What we know:

• Vitamin D is found naturally in a limited number of foods, but it may also be added to foods via fortification.
• Vitamin D rich foods include fortified dairy or soy products, fatty fish such as salmon, mackerel, sardines and tuna, eggs, margarine, and cod liver oil.
• Our bodies can also synthesize vitamin D from exposure to sunlight.
• The main function of vitamin D in the body is to maintain adequate blood levels of calcium and phosphorous by maximizing their absorption.
• Recent research has indicated that obtaining an adequate amount of vitamin D may protect against cancer, high blood pressure, osteoporosis, and certain autoimmune diseases.

What you should know:

• Certain groups of people are at a higher risk of vitamin D deficiency, though anyone with a reduced intake and sunlight exposure may also be at risk.
• People most at risk include the elderly, exclusively breast-fed infants, pregnant women, obese individuals, those with darker skin pigmentation, and those living in northern climates.
• In Canada, our skin cannot obtain enough sunlight to produce vitamin D during most of the year because the sun’s rays are too weak throughout the fall, winter, and spring months.

What you should do:

• Ensure vitamin D rich foods are consumed on a daily basis, especially for those at higher risk of deficiency.
• A vitamin supplement is also a good option when intake may not be adequate.
• Multi-vitamins usually contain about 200-400IU of vitamin D but supplements containing up to 1000IU is acceptable.
• The maximum amount one should consume from supplements and food combined is 2000IU for adults and 1000IU for children, as it is possible to overdose.

Also, exposing your skin to the sun for no more than 10-15 minutes without sunscreen may provide adequate vitamin D during the summer months.