Are You Getting Enough of the “Sunshine Vitamin”?
Vitamin D is essential for your body to maintain normal blood levels of calcium and phosphates for bone formation and remodeling. Research is still uncovering other potential roles too, like the prevention of heart disease, colorectal cancer and multiple sclerosis, as well as regulating the immune system. So, you know that vitamin D is important, but are you getting enough? Read on to learn more about the different sources of this “sunshine vitamin” that can help you meet your needs.
Vitamin D from Sunshine
Many people rely on the sun for their dose of vitamin D, hence the nickname “sunshine vitamin”. When exposed to the sun, ultraviolet B (UVB) radiation converts a cholesterol precursor in your skin (7-dehydrocholesterol) into vitamin D3, which then gets converted into calcitriol, the biologically active hormonal form.
Unfortunately, we don’t get enough sun in Canada to produce adequate vitamin D in our skin, especially with Canada’s short-lived summers. Our skin’s ability to make vitamin D also decreases as we age. Bummer, right? In Canada, vitamin D from sunlight exposure can only be synthesized in bare skin during late spring, summer, and early fall. Even still, there is just a 4-hour window of opportunity from 10am to 2pm and the UV index must be above 3 for vitamin D synthesis to work its magic.
How much time you need to spend under the sun depends on several things:
Amount of clothing worn
In general, 5-15 minutes of unprotected sun exposure a few times a week (granted it’s the right time of year) is thought to be enough time to produce adequate vitamin D. With the increased risk of skin cancer from UVA and UVB radiation and individual sensitivities to the sun, however, caution is recommended during unprotected sun exposure for any amount of time.
Food Sources of Vitamin D
Few foods we commonly consume naturally contain a lot of vitamin D. For this reason, some foods like cow’s milk, nondairy beverages, and margarine are fortified with vitamin D in Canada.
The following are some common foods with at least 50 IUs of vitamin D:
125 mL/ ½ cup fortified orange juice
250 mL/ 1 cup fortified soy, rice, oat or almond beverage
250 mL/ 1 cup milk (3.3% homo, 2%, 1%, skim, chocolate milk)
175g/ ¾ cup fortified yogurt (plain, fruit bottom)
2 large eggs with yolks
75g/ 2 ½ oz oily fish like salmon or trout (canned or cooked)
To Supplement or Not
Healthy children and adults require 600 IUs of vitamin D each day according to Canadian Dietary Reference Intakes (DRIs). For some, supplementation might be necessary to meet the DRIs. Vitamin D is available in two forms: vitamin D2 and vitamin D3. Both are effective at raising blood levels, but the best supplement to buy is vitamin D3 (cholecalciferol). It’s important to check with your doctor and pharmacist before starting a vitamin D supplement and have your blood levels checked to determine your individual needs.