Those who suffer from seasonal affective disorder (SAD) tend to feel sad, anxious, fatigued, hopeless and irritable during Fall and Winter due to the shorter days and reduced daylight. Antidepressants, light therapy, psychotherapy or a combination of these are typically used as treatments for SAD. But what about vitamin D? Should it be considered as an alternative treatment?

Some connections between SAD and vitamin D levels make for a good argument to consider vitamin D as a potential treatment for SAD. For example, SAD and depression are more likely to occur in people who have lower vitamin D levels compared to non-depressed people.[1][2]  Scientists studied this by providing SAD patients with very high doses of vitamin D. The depression scales of these patients showed improvement, as measured by the Hamilton Depression scale. The number of patients that were involved in this study was very small.1

Other theories that make scientists wonder whether vitamin D might be a future option to treat SAD consist of several facts such as those mentioned below;

– Reduced sunlight causes havoc with one’s biological clock, which is responsible for regulating sleep[2]

– Sunlight impacts the delicate balance between dopamine and serotonin, the brain’s neurotransmitters which influence your mood[2]  

– Vitamin D levels fluctuate in the body based on the amount of sunlight available in the different seasons.[2]

Studies thus far show that there is a relationship between vitamin D and SAD, but not enough data exists to suggest that vitamin D may actually be an effective or safe treatment for SAD. Until we have more concrete data, it is unknown whether or not vitamin D may actually be able to treat people with SAD some day.

Keep in mind that maintaining healthy vitamin D levels is a good idea for general health. Taking time outside in the sun, allowing your skin to synthesize its own vitamin D naturally, might be refreshing and worth considering.

If you are experiencing signs and symptoms of SAD, go talk to your doctor right away. There are proven treatments that they can offer to help you feel better.

Learn about Ddrops® liquid vitamin D products here.

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Natalie Bourré is a Ddrops Guest Blogger. She is a mom of 4 young children, health writer  and social media consultant who is passionate about promoting good health for the entire family. She is keen to share scientific information about about vitamin D in an easy to understand fashion. She also truly listens to people’s input and as such, she welcomes you to connect, discuss and share your questions and feedback with her on our social media accounts.  


[1] Gloth FM 3rd, Alam W., Hollis B., Vitamin D vs broad spectrum phototherapy in the treatment of seasonable affective disorder. J Nutr Health Aging. 1999;3(1):5-7.

[2] Stewart AE, Roecklein KA, Tanner S, Kimlin MG. Possible contributions of skin pigmentation and vitamin D in a polyfactorial model of seasonable affective disorder. Med Hypotheses. 2014 Nov;83(5):517-25. Epub 2014 Sep 18.