Feeling SAD during the winter months?
Why do some people feel more “down” during the winter months? Even going so far as to develop SAD (Seasonal Affective Disorder)? Let’s learn more!
Bite-Sized Science
As the Earth makes its yearly journey around the sun, it can point towards or away from the sun. Pointing towards the sun means more daylight–and exposure to sunlight is the best way to have adequate levels of Vitamin D.
Vitamin D is a chemical that is very important for a variety of processes in your body, including regulating your mood. Although there are likely multiple contributing factors to developing SAD, scientists think low levels of Vitamin D from inadequate sun exposure could be a contributing factor for SAD.
A Closer Look
Vitamin D is actually not a vitamin, but a hormone. A hormone is a chemical that helps transmit messages throughout the body. One of the messages that Vitamin D transmits through its action as a transcription factor is to promote the synthesis of a neurotransmitter, serotonin. The idea is that if you don’t have adequate amounts of vitamin D, it leads to there being less serotonin available, which can impact your mood.
Although vitamin D is artificially added to some foods, there are very few dietary sources of vitamin D. Going outside without sunscreen for a few minutes each day will help keep your vitamin D levels high. This again underscores the relationship between sunlight exposure and the development of SAD. Keep in mind that the amount of sunlight exposure can also be influenced by latitude and skin tone.
Please know that I am not a medical doctor! If you think you have SAD or want to explore if vitamin D supplementation is the right choice for you, please talk to your doctor.
Suggestions for Teaching
Have students generate a list of foods or drinks containing Vitamin D. Which ones do they like to eat or drink?
Have students examine other explanations beyond Vitamin D for why SAD can develop. Have students come up with a list of strategies/resources to use if they feel depressed and/or how to recognize the signs of SAD.
Have students investigate the relationship between vitamin D exposure and the evolution of human skin color. I highly recommend this HHMI video!