Vitamin D & Mental Health Is there a connection between vitamin D deficiency and 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.

We asked Naturopathic Doctor Julie Hwang (ND) for her thoughts on vitamin D deficiency and the role it plays in depression and mental health. Naturopathic doctors combine conventional medicine diagnostics with nutrition, lifestyle acupuncture, 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. For 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, not UVB. UVA rays cannot be converted to vitamin D.

Diagram showing ultraviolet rays from the sun that reach the earth come in the form of UVA and UVB. UVB rays help the body produce vitamin D.

What role does vitamin D play in the body, and how is it connected to mental health?

Significant research has shown that vitamin D is critical to 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. Some interesting research shows that there are vitamin D receptors in the brain that are known to play a key role in mood regulation. There is a strong correlation between vitamin D deficiency and depression, but whether it can be used as a treatment is not yet clear. Available studies are not robust enough to make specific recommendations, but it’s clear vitamin D plays an important role in the body.

Here are some interesting research findings and uses:

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 13-20 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 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:

1. 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
2. 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
3. Holick, M.F. (2017). The vitamin D deficiency pandemic: Approaches for diagnosis, treatment and prevention. Rev Endocr Metab Disord, 18(2):153-165.
4. 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
5. 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
6. 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
7. 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