Know Your Nutrients: Vitamin D

What is vitamin D?
Vitamin D is a fat-soluble vitamin, which means that it is stored in the liver and fatty tissues in your body. But it is unique in that it is also considered to be a hormone. One of vitamin D’s main roles is to aid in the absorption of calcium and phosphorus, helping to build and maintain strong bones and teeth.

What are some of the health benefits of vitamin D?
Vitamin D has long been known for its role in supporting strong and healthy bones. In fact, vitamin D deficiency used to be associated solely with bone-weakening diseases such as rickets in children and osteomalacia and osteoporosis in adults. More recently however, research has shown that vitamin D may also be beneficial for protecting against cancer, heart disease and diabetes, as well as maintaining a healthy immune system. It is widely considered to be the essential nutrient required throughout all ages and stages of life.

Can I get all of the vitamin D I need from the sun?
Vitamin D has long been known as the “sunshine vitamin” because we can naturally produce it in our bodies during exposure to ultraviolet B (UVB) rays in the sun. Unfortunately, many factors limit our ability to produce vitamin D from sun exposure:

  • Limited sun exposure during the fall and winter months (October to March)
  • Sunscreen use
  • Heavy clothing
  • Dark skin pigmentation
  • Cloudy skies and/or air pollution
  • Body’s ability to produce vitamin D declines with age

Where can I find vitamin D in my diet?
There are very few dietary sources of vitamin D. These include:

  • Milk in Canada is fortified with vitamin D (approximately 100 IU per cup). However, lactose intolerance or a general dislike for dairy products means that many of us are not drinking milk.
  • Fatty fish such as salmon, cod and herring
  • Butter
  • Egg yolks

Our limited ability to produce vitamin D from the sun, combined with the fact that there are few food sources of this nutrient, has led to widespread vitamin D deficiencies in Canada. This makes it especially important to ensure that you obtain enough vitamin D by taking a daily supplement.

How much vitamin D do I need each day?
Health Canada recommendation:

  • 600 IU/ day of vitamin D
  • This is the amount required each day to prevent vitamin D deficiency. However, recent scientific evidence suggests that vitamin D recommendations are too low. While many researchers now advise increasing daily vitamin D intake to 800 to 1,000 IU for optimal health, this amount is still well below the safe upper intake level of 4,000 IU per day established by the National Academy of Sciences.

Canadian Cancer Society recommendation:

  • 1,000 IU/ day of vitamin D during the fall and winter months with the advice of one’s healthcare practitioner
  • The Society also recommends that those at higher risk of having low vitamin D levels – older adults, individuals with dark skin, those who spend significant time indoors and those who wear clothing that covers most of their skin – consider taking 1,000 IU of vitamin D daily all year-round

Keep in mind it’s hard to meet this requirement through food alone. For example, each cup of milk in Canada is fortified with about 100 IU of vitamin D. So you would have to drink 10 cups of milk every day in order to get 1,000 IU of vitamin D

When should I take my vitamin D supplement?
Vitamin D is fat-soluble, and you will absorb it better in the presence of dietary fat. Therefore, try to consume vitamin D with a meal or snack to boost its absorption in your body.

Are there any supplements I should avoid taking with vitamin D?
Vitamin D can safely be taken alongside many other natural health products. It is best to consult a healthcare practitioner prior to use if you are taking any anti-epileptics, anti-tuberculosis drugs, lipid-lowering drugs, corticosteroids, or weight loss drugs.

Recipe: Tomato-Basil Salmon
Salmon is a fatty fish that naturally contains vitamin D (about 450 IU of vitamin D per 3-oz serving of sockeye salmon). This easy-to-prepare baked dish pairs well with a side of sautéed spinach or freshly steamed asparagus.

1. Preheat oven to 375F (190C).
2. Line a baking sheet with aluminum foil and grease with a light coating of vegetable oil, or spray with non-stick cooking spray.
3. Place two 6-ounce boneless, skinless salmon fillets onto the baking tray, then top with the following (ingredients to be divided between the two fillets):

  • 1 ½ tbsp dried basil
  • 1 clove freshly minced garlic
  • 1 tomato, sliced
  • 1 tbsp olive oil
  • 3 tbsp freshly grated Parmesan cheese

Bake for about 20 minutes, until salmon is opaque in the centre. Serve immediately.

Recipe adapted from:

Note: The information provided here is intended solely as a guideline and is not meant to treat, cure or prevent any condition or disease. Always consult a qualified healthcare practitioner prior to using any natural health product.