If you live in the upper half of the United States, chances are you aren’t getting enough vitamin D. The same goes for people in the northern latitudes all around the world. People with darker skin, the elderly, and obese/overweight people also tend to have lower levels of vitamin D. According to Harvard, one billion people worldwide have insufficient vitamin D in their blood.
Why do I care? Well vitamin D deficiency has been linked to a type of seasonal depression (also called seasonal affective disorder, or SAD…hehe). I was personally affected by this depression last winter.
About 10% of people are affected by SAD too. An example of SAD symptoms include:
- Lethargy, lacking in energy, unable to carry out a normal routine
- Sleep problems: finding it hard to stay awake during the day, but having disturbed nights
- Loss of libido or not interested in physical contact
- Anxiety; inability to cope
- Social problems, irritability, not wanting to see people
- Depression, feelings of gloom and despondency for no apparent reason
- Craving for carbohydrates and sweet foods, leading to weight gain
If you’re like me, you’re probably nodding “yes” to every symptom on this list. During the winter, the days are short and the nights are long. Most of us wake up and head to work before the sun is up, and come home after the sun sets. We don’t get enough time outside, and sometimes this leads to feelings of depression. You’re not alone.
So How are SAD and Vitamin D Deficiency Related?
To start, vitamin D levels in our body naturally change with the seasons. The more the sun is shining, the more likely you’ll have an adequate amount of “the sunshine vitamin” coursing through your body. In the winter months however, these levels can drastically drop, especially for those of us living in the colder areas of the world.
Vitamin D is also involved in the synthesis of serotonin and dopamine within the brain (source). Serotonin is considered the “human mood stabilizer,” while dopamine controls the brain’s reward and pleasure centers. It’s no wonder that low levels of these hormones are linked to depression.
So, combine the low levels of vitamin D in the winter with the lower levels of serotonin and dopamine being synthesized in your brain, and you have a really good recipe for seasonal depression. And to top it off with some science, this study actually found that people with lower levels of vitamin D showed more depressive symptoms than people with higher vitamin D levels.
How Can We Change This?
The best answer is to go outside and get some sun for 15 minutes a day! But for some of us, the UV index is constantly 0 during the winter. We need something better.
(And no, a tanning bed isn’t the answer because most tanning beds emit UVA light, and we need UVB light to stimulate production of vitamin D (source))
If the doc says it’s okay, try supplementing with vitamin D! This is the easiest and cheapest way to fix the problem. You can buy a bottle over the counter. The upper limit is said to be 4000 IU. I personally only use 2000 IU a day during the winter.
Plus, vitamin D provides a number of other benefits in addition to helping you with depression. The sunshine vitamin also:
- promotes strong healthy bones and teeth
- supports immune and nervous system (brain!)
- regulates insulin levels and helps with diabetic management
- supports lung function and cardiovascular health
- and many other wonderful benefits!
This article has a ton of cool facts if you want more.
I don’t typically like to use many supplements because I try my best to get my nutrients through food. But vitamin D is a big exception for me. I notice a huge difference in my mood and energy levels when I started taking my little gel capsule everyday. If you think you might be vitamin D deficient, simply ask your doctor for a test and go from there. Hope this helps!