Saskatchewan is known for its long, cold winters. As the temperatures decrease, so do the daylight hours, significantly diminishing the amount of sun we might see each day. To add to that, to avoid the cold, we spend more time indoors and the time we do spend outside has us wrapped from head-to-toe to keep warm. This means less sun exposure and therefore reduced opportunity for us to synthesize vitamin D from its light. For some people, the change in seasons also brings on the “winter blues” also known as Seasonal Affective Disorder (S.A.D.). It is currently thought that a combination of physiologic, psychologic, genetic, and environmental factors play a role in S.A.D., one of them being vitamin D deficiency.
What is seasonal affective disorder?
Also termed “S.A.D.”, Seasonal Affective Disorder is a form of depression that typically occurs in the winter months when our exposure to sunlight is limited. Approximately 2-3% of Canadians will experience S.A.D. at some point and 15% more will experience a milder version of the condition.
There is a natural tendency to slow down in winter compared to the high-energy lifestyles we tend to carry on in summer months. However, if you notice you are feeling particularly low or experiencing the signs & symptoms below, it might be time to consider consulting a healthcare professional for an assessment.
Signs & Symptoms
• Feelings of hopelessness & sadness
• Thoughts of suicide
• Oversleeping
• Cravings for sweet or starchy foods
• Weight gain
• Fatigue/low energy
• Decreased physical activity
• Difficulty concentrating
• Irritability
• Increased sensitivity to social rejection
• Avoidance of social situations
In S.A.D., these signs and symptoms appear and disappear at about the same time each year, and the sad, despairing mood:
• is present most days and lasts most of the day
• lasts for more than two weeks
• impairs performance at work, school or in social relationships
Vitamin D - the sunshine vitamin
Vitamin D, which actually functions more like a hormone, acts on receptors in every tissue in the body including the brain and immune system. As it is a fat-soluble vitamin, we get it through diet from sources such as fatty fish (sardines, salmon, tuna), eggs, and liver; and are also able to synthesize it through our skin when we get sufficient exposure to the sun. As such, vitamin D levels have been shown to fluctuate with exposure to sunlight. Levels tend to decline from fall to winter, and are naturally lower the further north you live from the equator.
Vitamin D has many functions within the body. It is needed for calcium absorption (healthy bones, teeth), healthy immune function, and also has a role in the release of dopamine and serotonin - signalling molecules that, in the brain, are associated with drive, pleasure, and happiness.
So, how much vitamin D do you need?
Health Canada recommends a daily dietary intake of 600-800 IU’s of Vitamin D for adults. However, according to their statistics, most Canadians are not achieving this. While we also know sunlight does provide Vitamin D, here in Saskatchewan, the exposure we get at our northern location is often inadequate, especially in the winter months. Vitamin D levels also decrease with age, skin pigmentation, liver and kidney disease, obesity, certain medications, genetic mutations and other conditions.
How do I know if I’m getting enough vitamin D?
Luckily, there is a test for that! A simple blood test can assess whether you are getting sufficient amounts of vitamin D, or if supplementation may be indicated–or, in some cases, contraindicated. There can be too much of a good thing especially when it comes to supplementation. Vitamin D toxicity related to excessive long-term intake of vitamin D can cause hypercalcemia and related symptoms such as confusion, apathy, vomiting, abdominal pain, pathological calcification, increased thirst and increased urination. It is also important to note that everyone metabolizes vitamin D differently, so some people can experience vitamin D toxicity even at lower doses that are considered safe for the general population. It is always recommended to consult a healthcare practitioner before implementing any new health regimen to see if it is right for you, including vitamin D supplementation.
If you are experiencing symptoms of the “winter blues” or are curious about your vitamin D status or other natural approaches to mental health, you are invited to book a consult with myself or one of my colleagues to discuss your healthcare options.
We look forward to working with you!
In health, Jacalyn Sieben, ND
References:
1. CAMH. (2019). Seasonal affective disorder (SAD). Retrieved from: https://www.camh.ca/en/health-info/ mental-illness-and-addiction-index/seasonal-affective-disorder
2. Canadian Mental Health Association, BC Division. (2013). Seasonal affective disorder. Retrieved from: https://cmha.bc.ca/documents/seasonal-affective-disorder-2/
3. Health Canada. (2012). Vitamin d and calcium: Updated dietary reference intakes. Retrieved from: https://www.canada.ca/en/health-canada/services/food-nutrition/healthy-eating/vitamins-minerals/ vitamin-calcium-updated-dietary-reference-intakes-nutrition.html
4. Marcinowska-Suchowierska E, Kupisz-Urbańska M, Łukaszkiewicz J, Płudowski P and Jones G (2018) Vitamin D Toxicity–A Clinical Perspective. Front. Endocrinol. 9:550. doi: 10.3389/fendo.2018.00550
5. Melrose S. (2015). Seasonal Affective Disorder: An Overview of Assessment and Treatment Approaches. Depression research and treatment, 2015, 178564. https://doi.org/10.1155/2015/178564
