Can Vitamin D Help With Depression?
Vitamin D, also known as the ‘sunshine vitamin’, is an important vitamin that often gets overlooked. Vitamin D deficiency is considered a global health problem that affects almost 50% of the population (more than 1 billion children and adults) worldwide. Even in Southeast Asia, where many countries enjoy sunshine all year round, Vitamin D deficiency is very common.

[Image Alternative Text: A globe with the Southeast Asia region highlighted in Red]
We ask Naturopathic Doctor Julie Hwang (ND), for her thoughts on vitamin D deficiency and the role it plays in mood and mental health. Naturopathic Doctors combine conventional medicine diagnostics with nutrition, lifestyle acupuncture, physical medicine and natural remedies and treatments.
Why are there high levels of Vitamin D deficiency in countries that have year-round sunlight?
The main source of Vitamin D exposure is via sunlight, but many factors can reduce the skin’s ability to produce Vitamin D. Here are some of the trends and risk factors we see:
1) Not getting enough sun exposure
Completely covering-up your body when you are in the sun or wearing sunscreen prevents your body from being able to absorb UVB rays to produce Vitamin D.
2) Not getting enough UVB ray exposure
Not all sunlight rays will convert to Vitamin D; only sunlight with sufficient UVB rays will convert Vitamin D into its active form when it touches the skin. As an example, in Jakarta, the highest intensity of UVB occurs between 11 a.m. to 1 p.m. The sunlight in the early morning and late afternoon contain mostly UVA, which can’t be converted to Vitamin D, not UVB.

[Image Alternative Text: Diagram showing that the ultraviolet rays from the sun that reach the earth come in the form of UVA and UVB]
What role does Vitamin D play in the body, and how is it connected to mental health?
Vitamin D is mostly known for its critical and most clearly researched role of helping the body absorb calcium and phosphorus from the small intestines. This is important for the growth and development of both bones and teeth. In addition to bone health, having low vitamin D levels can negatively impact your immune function.
What is most surprising about Vitamin D is the role it plays in so many other areas like mental health. There is a strong correlation between vitamin D and depression, but whether it can be used as a treatment is not clear yet. As an example, some interesting research shows that there are Vitamin D receptors in the brain that are known to play a key role in mood regulation.
Even though the available studies aren’t robust enough to make specific recommendations to really understand the role of vitamin D plays in mood, it’s clear it plays an important role in the body. Here are some interesting research findings and uses:
 | Depression during Pregnancy & Post-Partum Depression | A few small studies have shown that Vitamin D during pregnancy helped with depressive symptoms during pregnancy and post-partum |
 | Depression in Adults | A few studies have shown benefit in those with clinical depression that take Vitamin D alone or in combination with an antidepressant |
 | Depression and anxiety in women with Type 2 Diabetes | A small study showed that Vitamin D may help improve depression in anxiety in women with Type 2 Diabetes |
 | Depression in Childhood & Adolescents | Vitamin D has shown to have a possible role in some psychiatric conditions such as depression, attention deficit disorder and autism spectrum disorders |
How can people get more vitamin D?
It is important to know your body can’t make Vitamin D by itself, but there are a few options to increase levels in your body:
- Direct sunlight on your bare skin (such as face, legs, arms) a few times a week can help. Although there are no precise time-limits for being out in the sun to get the right amount of Vitamin D, most studies cite time limits between 13 – 30 minutes, from 3 times a week to daily.
- Certain food groups contain Vitamin D, such as cod liver oil, swordfish, salmon and egg yolks. Some mushrooms exposed to direct sunlight may also contain small levels of Vitamin D.
- Vitamin D supplements are also a readily available option.
If you think you may be at risk for low vitamin D, talk to a medical professional to get your levels tested and discuss what the best options may be.
References:
Holick, M.F. (2017). The vitamin D deficiency pandemic: Approaches for diagnosis, treatment and prevention. Rev Endocr Metab Disord, 18(2):153-165.
- Nimitphong, H., & Holick, M. F. (2013). Vitamin D status and sun exposure in southeast Asia. Dermato-Endocrinology, 5(1), 34–37. https://doi.org/10.4161/derm.24054
- Charoenngam, N., & Holick, M. F. (2020). Immunologic Effects of Vitamin D on Human Health and Disease. Nutrients, 12(7), 2097. https://doi.org/10.3390/nu12072097
- Penckofer S, Byrn M, Adams W, et al. Vitamin D Supplementation Improves Mood in Women with Type 2 Diabetes. J Diabetes Res. 2017;2017:8232863. doi:10.1155/2017/8232863
- Vaziri, F., Nasiri, S., Tavana, Z., Dabbaghmanesh, M. H., Sharif, F., & Jafari, P. (2016). A randomized controlled trial of vitamin D supplementation on perinatal depression: in Iranian pregnant mothers. BMC pregnancy and childbirth, 16, 239. https://doi.org/10.1186/s12884-016-1024-7
- Miyake, Y., Tanaka, K., Okubo, H., Sasaki, S., & Arakawa, M. (2015). Dietary vitamin D intake and prevalence of depressive symptoms during pregnancy in Japan. Nutrition (Burbank, Los Angeles County, Calif.), 31(1), 160–165. https://doi.org/10.1016/j.nut.2014.06.013
- Föcker, M., Antel, J., Ring, S., Hahn, D., Kanal, Ö., Öztürk, D., Hebebrand, J., & Libuda, L. (2017). Vitamin D and mental health in children and adolescents. European child & adolescent psychiatry, 26(9), 1043–1066. https://doi.org/10.1007/s00787-017-0949-3