If you don’t delight in gray days, long nights, and nearly constant rain, there’s no denying that winters here can be tough. And while we’re all equipped with our standard arsenal of reflective waterproof clothing and Elliott Smith tracks to get us through the darkest months, many people also rely on vitamin D supplements, which have gained something of a mythical reputation as a simple and complete chemical solution to keeping the gray-season blues at bay.

Anybody who has spent a winter in the Portland area has likely encountered a litany of vitamin D facts and fables. Many people will say that, second to sunlight, supplements are the best way to take in the nutrient, while others insist it's an exaggerated hoax. To set the record straight, here are a few facts regarding Seasonal Affective Disorder and vitamin D supplements:

• Every human brain contains chemical receptors that specifically receive vitamin D. These receptors are in an area of the brain also associated with depression. 
  
  
• According to research conducted in 2013 and made public by the Vitamin D Council, there is a significant correlation between vitamin D levels in the blood and the development of depression. However, it was inconclusive as to whether or not low levels of vitamin D were the cause of depression.
  
  
• According to the National Center of Biotechnology Information, extensive phototherapy tests (in which individuals are exposed to long periods of vitamin D-infused artificial sunlight) have concluded that “there is only modest evidence that vitamin D is effective at treating the symptoms of SAD.”
  
  
• The Mayo Clinic’s official stance is that “supplementation may improve symptoms of depression associated with SAD... More research is needed before a conclusion can be made.”

 

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In light of this information, it’s reasonable be skeptical of those who proselytize vitamin D supplements as some divine remedy. But that doesn’t mean vitamin D is unimportant for your physical well-being. According to Raleigh Warren, a chiropractic physician at Portland's Namaste Clinic, “Not only can vitamin D help with making stronger bones, but it can also protect against things like: osteoporosis, high blood pressure, cancer, immune system [support], Osteomalacia, fibromyalgia, fertility, multiple sclerosis, and the list goes on and on.”

While vitamin D’s chemical connection to depression is still a bit mysterious—just like most of the things that go on inside the human brain—it's true that vitamin D deficiency, if allowed to go unchecked, can lead to a slew of physical ailments, including aching joints and fatigue. These discomforts can be avoided by “as little as 10 minutes of exposure to the sun” per day (according to Warren) during the sunny months, and supplements during the upcoming dark season. If supplements don’t appeal to you, it’s possible to boost your vitamin D levels through mindful diet—certain kinds of fish, like wild salmon and mackerel, are good sources of the nutrient.

So, while vitamin D supplements can be an effective and inexpensive way to promote physical health after the sun goes behind the clouds, current research suggests they might not be the best treatment if you find yourself weighed down by SAD-ness this winter. Depression is an illness that varies in its characteristics and severity; serious, debilitating depression should obviously be discussed with a healthcare professional, but for the more common, mild moodiness that most of us experience during the Portland winters, there are innumerable other ways to stay happy and active during the rainy season. For more, check out our six secrets to fighting Seasonal Affective Disorder.