For Men, Women, & Mental Health​

Seems too good to be true. How do you separate the hype from the science? Are there any drawbacks associated with vitamin D? Is it possible to take too much? In this article, we’ll try to sort this out. We’ll explore the many benefits of vitamin D as well as the myths surrounding it.

Vitamin D is important because it plays a crucial role in many aspects of health and well-being. These include:
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• Bone health: This is its most widely known benefit and also has the most science behind it. Vitamin D helps our bodies absorb calcium and phosphate, which are essential for building bone, from our intestines. It is important for preventing conditions like rickets in children and osteoporosis in adults. 
• Muscle health: Adequate vitamin D levels are essential for proper muscle function. Low vitamin D levels can lead to weaker muscles (NIH, 2022). 
• Immune system support: Vitamin D helps regulate the immune system. It may also play a role in reducing the risk of infections and can help manage autoimmune diseases such as multiple sclerosis (NIH, 2022).
• Cancer: Some research suggests that vitamin D may have a role in preventing or treating certain types of cancer (Bohon & Goolsby, 2013). But other studies found no effect, so more research is needed. 
• Moods and mental health: There is evidence to suggest that vitamin D may play a role in mood regulation, and deficiency has been linked to conditions like depression and seasonal affective disorder (SAD) (Penckofer et al., 2010). However, this could also be related to being outside and exercising, so again, more research is needed.
• Cognitive decline: Low blood levels of vitamin D have been associated with an increased risk of dementia (Harvard School of Public Health, 2023).
• Organ function: Vitamin D is involved in keeping the kidneys and intestines functioning properly (Alayed Albarri et al., 2022).

Vitamin D3 (cholecalciferol) is the form of vitamin D that your skin produces when exposed to sunlight. As far as food sources go, it’s mostly found in fatty fish. D3 is also found in lichens, one of the few plant-based sources. It’s the type of vitamin D that’s more commonly used to fortify foods and is the form used in supplements. (As a vegan, I see that this is the source of vitamin D in my multivitamin.)

Although not conclusive, studies suggest that D3 is more effective at raising the level of vitamin D in your blood than D2 (Tripkovic et al., 2012), so many healthcare professionals prefer prescribing vitamin D3 for treating vitamin D deficiencies.

• Bone health: Vitamin D is crucial for bone health in women, especially as we age. Women over 50 years old have a rate of osteoporosis four times higher than men and are more prone to bone fractures (Alswat, 2017). 
• Menstrual health: Some research has indicated that vitamin D may have a role in regulating menstrual cycles and reducing the risk of conditions like polycystic ovary syndrome (PCOS) (Łagowska, 2018).
• Pregnancy and fetal development: Maintaining an adequate level of vitamin D is especially important when you’re pregnant. First, it supports the development of the baby’s bones and immune system. It can even affect the long-term health of children. In addition, low vitamin D in pregnant women has been associated with high blood pressure, gestational diabetes, preterm delivery, and postpartum depression (Mithal & Kalra, 2014). It’s important to consult with your healthcare professional to determine the appropriate amount of vitamin D needed during pregnancy. 
• Cancer prevention: While research is ongoing, some studies have suggested that adequate vitamin D levels may be associated with a reduced risk of certain types of cancer, including breast and ovarian cancer (Bohon & Goolsby, 2013).

• Testosterone levels: While more research is needed, ensuring sufficient vitamin D intake may help maintain healthy testosterone levels (Pilz et al., 2011). Low testosterone can lead to a range of issues including decreased muscle mass, low energy levels, and sexual dysfunction.
• Prostate cancer prevention: There is ongoing research into the potential role of vitamin D in reducing the risk of certain cancers. Some studies have suggested that adequate vitamin D levels may help protect against the development of prostate cancer (Song et al., 2018).
• Sexual health: Vitamin D deficiency is associated with erectile dysfunction and fertility issues (Canguven & Al Malki, 2021).

One study with women experiencing hair loss found that many of the participants also had vitamin D deficiency. The researchers suggested that taking supplements might help, but they also acknowledged that other factors could be at play. For example, hair loss in women can trigger stress, which might discourage them from going outdoors as much, so they’re getting less sun exposure (Gerkowicz et al., 2017).  

A review of the scientific literature on the role of vitamin D in hair loss did show a relationship between low levels of vitamin D in the blood and hair loss. But, just like with weight loss, there isn’t evidence showing vitamin D corrects hair loss (Saini & Mysore, 2021). 

Personally, I found this disappointing. As I’m getting older, I’ve noticed my hair is getting a bit thinner, and I’d love to be able to just take some vitamin D to fix it! 

While vitamin D is essential for health, including the benefits described above, excessively high doses, over 4,000 IU (international units) or 100 mcg, have not been linked to additional health benefits (Harvard Medical School, 2022). In fact, at such high doses it can have adverse health effects and can even be toxic. Excessive levels of vitamin D toxicity cause hypercalcemia (elevated calcium levels in the blood), which has symptoms such as nausea, vomiting, weakness, and kidney stones. Extremely high doses can cause kidney failure, irregular heartbeat, and even death (NIH, 2022). 

The bottom line is that more is not necessarily better—and it can actually be worse (Harvard Medical School, 2022). So to avoid harmful effects, don’t take more than the highest recommended amount unless prescribed by a health professional. 

One thing to consider is that while breast milk is an excellent source of nutrition for infants, it may not provide enough vitamin D. This is because the amount of vitamin D in breast milk is generally low. A breastfeeding mother who has an adequate intake of vitamin D will have some of the nutrient in her breast milk, but it may still not be enough to meet the infant’s needs. 

Also, sun exposure isn’t recommended for babies because their skin is too delicate and sensitive. Many pediatricians recommend vitamin D supplements for infants, especially if they are exclusively breastfed. The American Academy of Pediatrics recommends that all infants, including those who are breastfed, receive a daily vitamin D supplement of 400 IU per day. These supplements are typically available in liquid form and can be administered orally.
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But don’t overdo it. As discussed above, excessive intake of vitamin D supplements can lead to toxicity, which can be harmful. 

I took a look at my multivitamin, and it contains 25 mcg (1,000 IU), so it has more than enough. But not all multivitamins do, so it’s a good idea to check your multivitamin and think about adding a vitamin D tablet if needed.

• Depression: A review of published research supports a correlation between depression and vitamin D, but the relationship between the two isn’t clear (Menon et al., 2020). In other words, we can’t say that one causes the other. There could be other related factors such as obesity, age, and not spending as much time outdoors. In addition, several clinical studies didn’t show evidence that treating depression with vitamin D had any effect (NIH, 2022; Guzek et al., 2021).  
• Seasonal affective disorder (SAD): Some studies suggest a connection between low vitamin D levels and an increased risk of SAD. The researchers believe that reduced exposure to sunlight during these seasons may contribute to both lower vitamin D levels and mood disturbances.
• Cognitive function: Some researchers have explored the potential role of vitamin D in cognitive function and the risk of conditions like dementia and Alzheimer’s disease. While there is evidence that adequate vitamin D levels may support cognitive health, the exact mechanisms are not well understood. There are vitamin D receptors in various areas of the brain, suggesting a potential role in neurological function. Additionally, vitamin D is involved in the production of neurotransmitters like serotonin, which is associated with mood regulation.

• Wound healing: Vitamin D is involved in the production of antimicrobial proteins, which promote wound healing. These proteins reduce skin inflammation and help reestablish cells that make up the skin barrier (Mostafa & Hegazy, 2015).
• Skin aging: Some studies indicate that vitamin D has photoprotective effects on the skin. In other words, it can help protect the skin from aging and cancer due to sun exposure. This may be partly due to its anti-inflammatory properties (Bocheva et al., 2021; Mostafa & Hegazy, 2015).
• Psoriasis: Some research suggests that vitamin D can be beneficial for people with psoriasis, a chronic condition characterized by red, scaly patches on the skin. However, topical vitamin D may be more beneficial than tablets for this condition (Mostafa & Hegazy, 2015).
• Acne: There is some evidence to suggest that vitamin D may have a role in reducing inflammation associated with acne (Mostafa & Hegazy, 2015).

But some benefits have been overblown in the media, especially the benefits of megadose vitamin D, which can be harmful and even deadly. So it’s important to strike a balance and ensure you get the right amount of vitamin D through sunlight, diet, or supplements without overdoing it. 

• Alswat, K. A. (2017). Gender disparities in osteoporosis. Journal of Clinical Medicine Research, 9(5), 382.
• Bocheva, G., Slominski, R. M., & Slominski, A. T. (2021). The impact of vitamin D on skin aging. International Journal of Molecular Sciences, 22(16), 9097.
• ​​Bohon, T. M., & Goolsby, M. A. (2013). The role of vitamin D supplements in women’s health. Clinical Medicine Insights: Women’s Health, 6, CMWH-S11067.
• Canguven, O., & Al Malki, A. H. (2021). Vitamin D and male erectile function: an updated review. The World Journal of Men’s Health, 39(1), 31.
• Cleveland Clinic. (2022). Vitamin D deficiency: Causes, symptoms & treatment. https://my.clevelandclinic.org/health/diseases/15050-vitamin-d-vitamin-d-deficiency 
• Alayed Albarri, E. M., Sameer Alnuaimi, A., & Abdelghani, D. (2022). Effectiveness of vitamin D2 compared with vitamin D3 replacement therapy in a primary healthcare setting: A retrospective cohort study. Qatar Medical Journal, 2022(3), 35.
• Gerkowicz, A., Chyl-Surdacka, K., Krasowska, D., & Chodorowska, G. (2017). The role of vitamin D in non-scarring alopecia. International Journal of Molecular Sciences, 18(12), 2653.
• Gupta, N., Farooqui, K. J., Batra, C. M., Marwaha, R. K., & Mithal, A. (2017). Effect of oral versus intramuscular Vitamin D replacement in apparently healthy adults with Vitamin D deficiency. Indian Journal of Endocrinology and Metabolism, 21(1), 131.
• Guzek, D., Kołota, A., Lachowicz, K., Skolmowska, D., Stachoń, M., & Głąbska, D. (2021). Association between vitamin D supplementation and mental health in healthy adults: a systematic review. Journal of Clinical Medicine, 10(21), 5156.
• Harvard Medical School. (2022). Taking too much vitamin D can cloud its benefits and create health risks. https://www.health.harvard.edu/staying-healthy/taking-too-much-vitamin-d-can-cloud-its-benefits-and-create-health-risks
• Harvard School of Public Health. (2023). Vitamin D. https://www.hsph.harvard.edu/nutritionsource/vitamin-d/
• Łagowska, K. (2018). The relationship between vitamin D status and the menstrual cycle in young women: a preliminary study. Nutrients, 10(11), 1729.
• Menon, V., Kar, S. K., Suthar, N., & Nebhinani, N. (2020). Vitamin D and depression: a critical appraisal of the evidence and future directions. Indian Journal of Psychological Medicine, 42(1), 11–21.
• Mithal, A., & Kalra, S. (2014). Vitamin D supplementation in pregnancy. Indian Journal of Endocrinology and Metabolism, 18(5), 593.
• Mostafa, W. Z., & Hegazy, R. A. (2015). Vitamin D and the skin: Focus on a complex relationship: A review. Journal of Advanced Research, 6(6), 793–804.
• Narvaez, J., Maldonado, G., Guerrero, R., Messina, O. D., & Rios, C. (2020). Vitamin D megadose: definition, efficacy in bone metabolism, risk of falls and fractures. Open Access Rheumatology: Research and Reviews, 105–115.
• National Institutes of Health. (2022). Vitamin D fact sheet for health professionals. NIH Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/
• Penckofer, S., Kouba, J., Byrn, M., & Estwing Ferrans, C. (2010). Vitamin D and depression: where is all the sunshine? Issues in Mental Health Nursing, 31(6), 385–393.
• Pilz, S., Frisch, S., Koertke, H., Kuhn, J., Dreier, J., Obermayer-Pietsch, B., . . . & Zittermann, A. (2011). Effect of vitamin D supplementation on testosterone levels in men. Hormone and Metabolic Research, 43(03), 223–225.
• Saini, K., & Mysore, V. (2021). Role of vitamin D in hair loss: A short review. Journal of Cosmetic Dermatology, 20(11), 3407–3414.
• Song, Z. Y., Yao, Q., Zhuo, Z., Ma, Z., & Chen, G. (2018). Circulating vitamin d level and mortality in prostate cancer patients: A dose–response meta-analysis. Endocrine Connections, 7(12), R294–R303.
• Taylor, P. N., & Davies, J. S. (2018). A review of the growing risk of vitamin D toxicity from inappropriate practice. British Journal of Clinical Pharmacology, 84(6), 1121–1127.
• Tripkovic, L., Lambert, H., Hart, K., Smith, C. P., Bucca, G., Penson, S., . . . & Lanham-New, S. (2012). Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: a systematic review and meta-analysis. The American Journal of Clinical Nutrition, 95(6), 1357–1364.