Written By: Samara Mascarenhas, Indigenous Youth Health Project Co-Lead
Vitamin D has been at the forefront of public health and health promotion sectors in the few years since research has proven its significant capabilities for overall human health. Within Canada, the benefits of vitamin D have been promoted at both the community and policy level through wide-scale campaigns and food & drug regulation policies. Despite Canada’s efforts, there continues to be a great disconnect between the abundance of information provided and knowledge obtained. More than 20% of young Canadian adults have shared that they have trouble identifying vitamin D sources, the appropriate vitamin D intake required and amount of sun exposure required to produce adequate vitamin D (Boland et al., 2015). A large reason for this is due to resources being scientifically dense, not literacy friendly and inaccessible. To overcome this, a simple beginners overview of vitamin D, intake recommendations, sources, and additional references are provided below.
What is Vitamin D?
Vitamin D has been classified by Health Canada as an essential nutrient and hormone that supports healthy bone and immune function, regulates the absorption of calcium and phosphorus and aids in the prevention of numerous chronic illnesses, including cardiovascular disease, bone diseases, diabetes and cancer (Harvard, 2022; Naeem, 2010; Schwalfenberg, Genuis, & Hiltz, 2010). Higher levels of vitamin D can also help regulate moods and reduce the incidence of negative emotions experienced amongst individuals with pre-existing conditions of depression or anxiety (Cheng, Huang, & Huan, 2019).
How much Vitamin D do we need?
The amount of vitamin D recommended is largely based on an individual's age, lifestyle and any other pre-existing conditions that have been diagnosed. Prior to taking a vitamin D supplement please consult your physician or a healthcare professional.
For reference, an updated list of recommended dietary allowance for vitamin D intake can be found on the Government of Canada’s website. Recommended Dietary Allowance (RDA) simply refers to the level of intake recommended per day, while the Tolerable Upper Intake Level refers to the maximum level that can be taken per day that poses no risks for negative health effects. Vitamin D intake levels are often referred to by the potency represented as an international unit (IU). Vitamin D supplements will state how much (i.e. drop, tablet etc) is equal to a certain amount of IU.
The Recommended Dietary Allowance (RDA) for young children and adults between 9 to 70 years of age is 600 IU per day, with a Tolerable Upper Intake Level of 4000 IU per day. In the winter, more than 40% of Canadians are below the appropriate cut-off of vitamin D levels recommended compared to 25% of Canadians in the summer (Aziz, 2022). Canadian young adults aged 20 to 39 also make up one of the most susceptible groups in Canada that are vitamin D deficient, with 66% of young adults reporting that they do not take vitamin D supplements and 41% falling below the Recommended Dietary Allowance (RDA) equivalent to 600 IU per day (Janz & Pearson, 2015).
It is vital that your Vitamin D levels are checked to ensure that you are not deficient or are at an excess prior to taking vitamin D supplements. Many Canadian physicians within Canada will not recommend a vitamin D blood test to be taken unless they suspect chronic conditions that may affect vitamin D levels such as osteoporosis. However, many individuals with vitamin D deficiency can experience periods of asymptomatic symptoms, leading to higher rates of being undiagnosed. If you suspect yourself to be vitamin D deficient or have never checked your own vitamin D levels, now might be a good time.
How to Test for Vitamin D
The most accurate way to measure vitamin D levels in the body is through a blood test. You can request a vitamin D blood test requisition from your family doctor or from a healthcare professional. Within Canada vitamin D levels are measured according to nanomoles (nmol) per liter (L). The appropriate range for vitamin D levels is between 30 nmol/L - 125 nmol/L. Important to note however, vitamin D tests across many provinces and territories are not covered by Canada’s healthcare funds. Please refer to your own provinces or territories appropriate testing costs.
Sources of Vitamin D
Vitamin D2, originating from plant sources and vitamin D3 originating from animal sources are the two main natural forms of vitamin D. Physicians will often recommend patients to supplement with vitamin D3 sources in comparison to vitamin D2, since D3 is more superior at raising vitamin D levels in the body for longer periods of time.
Humans are also able to produce a sufficient amount of vitamin D3 when their skin is exposed to ultraviolet rays from the sun for a period of 5 - 10 minutes a few times during the week. However, when fewer sunlight rays are present during the winter months, Canadians may not be able to absorb a sufficient amount of vitamin D (Langlois et al., 2015). Supplementing with vitamin D supplements has been regarded as the best way to obtain a sufficient amount of vitamin D during the winter months when sunlight exposure is low. Vitamin D2 and D3 supplements are available in Canada in various options including liquid, tablets, chewables and gummies. When taking a supplement for vitamin D it is recommended that you take one that is made with oil, or consume while eating sources of healthy fat (i.e. avocado) sinceVitamin D is significantly better absorbed (up to 32%) in the bloodstream when it is consumed with a healthy amount of fat-soluble sources (Dawson-Hughes et al., 2014).
Incorporating foods that are rich in vitamin D is also another great way to ensure you are maintaining a healthy level. Common food sources available in Canada that are rich in vitamin D include:
Vitamin D2 Sources
Mushrooms
Fortified foods (including goats milk, orange juice, dairy or plant based milks, yogurt, cereals)
Vitamin D3 Sources
Fatty fish (salmon, swordfish, tuna, mackerel)
Fish oil (cod liver oil)
Beef and Pork liver
egg yolks, and some cheeses
Vitamin D Resources
There has been a lot of information to unpack in this guide. If you would like to learn more about vitamin D and its importance please check out some of the amazing resources referenced below.
Vitamin D Fact Sheet - MS Society of Canada
Kids Health Information: Vitamin D
The Nutrition Source: Vitamin D
References:
Aziz, S. (2022). Vitamin D Deficiency: Who is at Risk and How to Keep up Levels this Winter. Global News. Retrieved from: https://globalnews.ca/news/9328990/vitamin-d-deficiency-winter-canada-risks/
Boland, S., Irwin, J. D., & Johnson, A. M. (2015). A Survey of University Students’ Vitamin D–Related Knowledge. Journal of Nutrition Education and Behavior, 47(1), 99–103. https://doi.org/10.1016/j.jneb.2014.08.013
Cheng, Y. C., Huang, Y. C., & Huang, W. L. (2020). The effect of vitamin D supplement on negative emotions: A systematic review and meta‐analysis. Depression and anxiety, 37(6), 549-564. https://doi.org/10.1002/da.23025
Dawson-Hughes, B., Harris, S. S., Lichtenstein, A. H., Dolnikowski, G., Palermo, N. J., & Rasmussen, H. (2015). Dietary fat increases vitamin D-3 absorption. Journal of the Academy of Nutrition and Dietetics, 115(2), 225-230. Retrieved from: https://www.sciencedirect.com/science/article/pii/S2212267214014683
Harvard T.H Chan (2022). Vitamin D. Harvard School of Public Health. Available from: https://www.hsph.harvard.edu/nutritionsource/vitamin-d/#:~:text=It%20is%20a%20fat%2Dsoluble,control%20infections%20and%20reduce%20inflammation.
Janz, T., & Pearson, C. (2015). Vitamin D blood levels of Canadians. Statistics Canada. https://www150.statcan.gc.ca/n1/pub/82-624-x/2013001/article/11727-eng.htm
Langlois, K., Greene-Finestone, L., Little, J., Hidiroglou, N., & Whiting, S. (2015). Vitamin D status of Canadians as measured in the 2007 to 2009 Canadian Health Measures Survey. Health Reports, 21(1), 47–55. https://www150.statcan.gc.ca/n1/pub/82-625-x/2010001/article/11137-eng.htm
Naeem Z. (2010). Vitamin D deficiency – an ignored epidemic. International Journal of Health Sciences, 4(1), V-VI. PMID: 21475519
Schwalfenberg, G. K., Genuis, S. J., & Hiltz, M. N. (2010). Addressing vitamin D deficiency in Canada: a public health innovation whose time has come. Public health, 124(6), 350-359.https://doi.org/10.1016/j.puhe.2010.03.003