By Dr. Gail Sauer

It’s that time again. Our moods fall as quickly as Autumn leaves being exposed to a harsh wind. Statistics show that up to 35% of Canadians suffer from winter blues, 15% of which suffer from mild to moderate seasonal depression. That is quite a lot of people!

There are a few major factors that contribute to SAD. Decreases in sunlight exposure result in lowering vitamin D levels, as well as changes in circadian rhythm (due to an increase in dark hours in the day). Circadian rhythm changes affect neurotransmitter balance and can results in low serotonin and/or high melatonin.

Now, how does this apply to you?


It is estimated that over 1 billion people suffer from a vitamin D deficiency. Vitamin D deficiency contributes to the onset of numerous conditions: cancer, osteoporosis, fibromyalgia, cardiovascular disease, diabetes and plays a role in depression and other mental health disorders. Research has shown that supplementing vitamin D at doses of 400-600IU per day in individuals who are low to deficient does not result in an increase of overall vitamin D levels. Consequently, when levels are low, higher doses (7000-10,000IU per day) of vitamin D are needed to remedy low levels.

Supporting vitamin D levels in Fall and Winter can be done by supplementing vitamin D orally, in a liquid form for best absorption, or through intramuscular injections. Monitoring your levels of vitamin D by doing regular blood work (a few times a year) to ensure your vitamin D levels are in good standing is recommended.


Now, a bit about the circadian rhythm changes: different hormonal and neurotransmitter changes occur with changes in light exposure. When daytime light lessens with Autumn, the production of our serotonin or “happy” hormone decreases. Eating carbohydrate rich foods naturally stimulates serotonin production. Hence many of us feel carbohydrate cravings come on this time of year. The usual (and typically unfortunate) side effect of these seasonal cravings is unwanted weight gain.


So instead of eating a bag of potato chips and a loaf of bread for dinner, what other things can we do to support serotonin levels?  Here is an easy-to-implement list:

  1. Support your gut health with gut healthy foods. Serotonin is produced in your large intestine. If your gut is compromised, serotonin levels will also be compromised. Gut healthy foods include foods that high in fiber, low in sugar and foods that contain healthy bacterial cultures (e.g., vegan coconut kefir, sauerkraut, kimchi).
  2. Exercise! Regular aerobic exercise (running, cycling, swimming, etc.) can increase serotonin levels and maintain healthy levels for one week after the exercise is terminated. For optimal balance, exercise for 30-60 minutes 5-6 days per week.
  3. Get a massage. Massage therapy has been shown to increase serotonin by a whopping 28%. Now we all have a wonderful excuse to lie down and be nurtured for an hour!
  4. Cut back on alcohol. Alcohol lowers the production of serotonin and contributes to depression. Instead, drink oat straw and dandelion tea. Both of these herbs help support serotonin levels.
  5. Meditate. Research conducted on participants of an 8-week mindfulness course demonstrated positive changes in grey matter in the brain during and after the course, specifically in the sites of the brain where both dopamine and serotonin are produced.
  6. Add Griffonia or 5HTP supplements. Supplemental forms of serotonin can be very effective in supporting mood during the winter months. Additionally, in a study group of overweight individuals, 5HTP has been shown to regulate carbohydrate cravings associated with low serotonin and optimize weight loss.  Please consult with an ND before taking these, however, as they can interact with some medications.

As the cold winds blow in, and we settle in to the warmth of our blankets and comforting teas, find solace in the knowledge that there is another sunny day just around the corner. Remind yourself in the dark moments, that there are simple interventions that can shift us back into better mood balance. And never hesitate to reach out for support.
Vitamin D and Depression: Where is all the Sunshine?
Brain serotonin, carbohydrate-craving, obesity and depression.
Exercise and Brain Neurotransmission.
Cortisol decreases and serotonin and dopamine increase following massage therapy.
Change in Brainstem Gray Matter Concentration Following a Mindfulness-Based Intervention is Correlated with Improvement in Psychological Well-Being.