Which Vitamin Deficiences Can Cause Hair Loss?

Article Summary

Hair loss is a complex issue influenced by various factors, including vitamin deficiencies. We explored the impact (or lack thereof) of deficiencies in five vitamins – Vitamin D, Biotin, Vitamin B12, Vitamin E, and Vitamin A – on hair health and whether supplementation can aid hair regrowth. While deficiencies in these vitamins can disrupt follicle function, growth cycles, and scalp health, the evidence supporting supplementation for non-deficient individuals is limited. The bottom line? Addressing documented deficiencies might improve hair health, but indiscriminate supplementation probably won’t yield meaningful results and could even be counterproductive.

Full Article

Hair loss affects millions of people worldwide, with over 80 million Americans experiencing notable balding or thinning by age 50. While genetics and aging are commonly cited causes of hair loss, nutritional deficiencies are frequently overlooked as a potential cause. Hair loss vitamin deficiency can manifest in various ways, from excessive shedding to slow regrowth and changes in hair texture.

This article will dive deeper into the key vitamins and nutrients essential for hair health, focusing on how their deficiencies can contribute to hair loss. We’ll examine how deficiencies in five different vitamins, including Biotin and Vitamins D, B12, E, and A, might contribute to hair loss and which, if any, are worth supplementing with.

Why Does A Lack of Vitamins Cause Hair Loss?

When the body lacks essential nutrients, it prioritizes vital organs over non-essential tissues like hair, leading to potential hair thinning and loss.^[1]Guo, E.L., Katta, R. (2017). Diet and hair loss: effects of nutrient deficiency and supplement use. Dermatology Practical & Conceptual. 7(1). 1-10. Available at: … Continue reading It is known that vitamins are important in every stage of hair cycling, however, the exact role that they play has not yet been elucidated.^[2]Almohanna, H.M., Ahmed, A.A., Tsatalis, J.P., Tosti, A. The role of vitamins and minerals in hair loss: a review. Dermatology and Therapy. 9(1). 51-70. Available at: … Continue reading 

They also facilitate important processes like protein synthesis, which is vital for producing keratin.^[3]Langova, L., Novotna, I., Nemcova, P., Machacek, M., Havlicek, Z., Zemanova, M., Chrast, V. (2020). Impact of nutrients on the hoof health in cattle. Animals. 10(10). 1824. Available at: … Continue reading Vitamins help protect hair cells from damaging oxidative stress, while B vitamins aid in cellular metabolism and growth.^[4]Choi, Y.H., Shin, J.Y., Kim, J., Kang, N.G., Lee, S. (2021). Niacinamide down-regulates the expression of DKK-1 and protects cells from oxidative stress in cultured human dermal papilla cells. … Continue reading 

When vitamin levels in the body are insufficient, hair follicles struggle to sustain healthy hair production. This nutrient deprivation interferes with several processes involved in hair growth, putting hair at risk of excessive shedding, slow growth, hair thinning, dullness, dryness, changes in texture, and even patchy hair loss.

1. Vitamin D

How Might Vitamin D Deficiency Contribute to Hair Loss?

Vitamin D is essential for maintaining hair follicle health and regulating immune responses, making it an essential nutrient for healthy hair growth. Due to its impact on follicular activity and immune modulation, a deficiency in Vitamin D has been linked to hair loss conditions, including alopecia areata.

Vitamin D directly influences the hair follicle cycle by interacting with Vitamin D receptors (VDRs) located in the hair follicle. These receptors are critical for initiating the anagen (growth) phase of the hair cycle.^[5]Demay, M.B., MacDonald, P.N., Skorija, K., Dowd, D.R., Cianferotti, L., Cox, M. (2007). Role of the vitamin D receptor in hair follicle biology. The Journal of Steroid Biochemistry and Molecular … Continue reading Without sufficient Vitamin D, keratinocytes cannot function optimally, meaning that they can’t produce sufficient keratin.^[6]Pavlovitch, J.H., Rizk, G.M., Didierjean, L., Balsan, S. Alterations in rat epidermis provoked by chronic vitamin D deficiency. The American Journal of Physiology. 247(2 Pt 1). E228-E233. Available … Continue reading This disruption can lead to premature shedding and hair thinning.

Vitamin D also has immunomodulatory properties that help regulate the immune system.^[7]Mele, C., Caputo, M., Bisceglia, A., Sama, M.T., Zavatorro, M., Aimaretti, G., Pagano, L., Prodam, F., Marzullo, P. (2020). Immunomodulatory effects of vitamin D in thyroid diseases. Nutrients. … Continue reading In autoimmune conditions like alopecia areata (AA), where the immune system attacks hair follicles, low levels of vitamin D exacerbate the problem. Studies have demonstrated significantly lower serum vitamin D levels in patients with AA compared to healthy individuals. One study showed that patients with AA had an average serum vitamin D level of 16.6 ng/mL compared to 40.5 ng/mL in control patients.^[8]Bhat, Y.J, Latif, I., Malik, R., Hassan, I., Sheikh, G., Lone, K.S., Majeed, S., Sajad, P. (2017). Vitamin D level in alopecia areata. Indian Journal of Dermatology. 62(4). 407-410. Available at: … Continue reading 

The same study also found a correlation between disease severity and vitamin D deficiency, suggesting that vitamin D plays a protective role against autoimmune-mediated hair loss.

Several other studies also underscore the link between vitamin D deficiency and hair loss.

• Animal studies have demonstrated that VDR mutations or dietary deficiencies in vitamin D lead to disrupted hair growth cycles and alopecia.^[11]Sakai, Y., Demay, M.B. (2000). Evaluation of keratinocyte proliferation and differentiation in vitamin D receptor knockout mice. Endocrinology. 141(6). 2043-2049. Available at: … Continue reading 
• In patients with AA, lower levels of vitamin D correlate with higher inflammation markers like CRP (C-reactive protein), further implicating its role in immune regulation.^[12]Kruit, A., Zanen, P. (2016). The association between vitamin D and C-reactive protein levels in patients with inflammatory and non-inflammatory diseases. Clinical Biochemistry.  49(7-8). 534-537. … Continue reading  

While we wouldn’t recommend only supplementing with vitamin D to treat your hair fall, if you suspect that a deficiency is partly to blame for the hair loss you are experiencing, then you could increase intake through sunlight exposure, dietary intake, or supplementation. However, you should probably get a blood test to confirm potential deficiencies.

2. Biotin

How Might Biotin Deficiency Contribute to Hair Loss

While biotin deficiency is a real cause of hair loss, there are some myths that should be dispelled about biotin supplementation. Biotin, also known as vitamin B7, helps maintain healthy hair, skin, and nails.

Biotin deficiency can lead to hair loss, as evidenced by several studies. One study conducted on 541 women complaining of hair loss found that 38% of women with hair loss were found to be biotin deficient (less than 100 ng/L of biotin), whereas 13% had optimal biotin levels (more than 400 ng/L).^[13]Trueb, R.M. Serum biotin levels in women complaining of hair loss. International Journal of Trichology. 8(2). 73-77. Available at: https://doi.org/10.4103/0974-7753.188040 Furthermore, the study found that women with low biotin levels were more likely to have seborrheic-like dermatitis alongside telogen effluvium than women with optimal biotin levels.

Supplementation can be beneficial for those with biotin deficiency. Patients with inherited enzyme deficiencies like biotinidase deficiency or holocarboxylase synthetase deficiency often experience alopecia that resolves after biotin supplementation. In these cases, larger doses of biotin (10,000 to 30,000 μg/day) are typically recommended.^[14]Patel, D.P., Swink, S.M., Castelo-Soccio, L. (2017). A review of the use of biotin for hair loss. Skin Appendage Disorders. 3(3). 166-169. Available at: https://doi.org/10.1159/000462981 

However, for healthy people without a deficiency, the efficacy of biotin supplementation for hair growth is not supported by strong scientific evidence. Despite its popularity in the media and amongst consumers, biotin has no proven efficacy in improving hair growth in healthy individuals.

So, while biotin deficiency can cause hair fall, it’s not a common cause for most people experiencing hair loss, and it is not likely to be the cure unless there is a biotin deficiency.

You can read more about exactly what we think about biotin supplementation for hair loss here.

3. Vitamin B12

How Might Vitamin B12 Deficiency Contribute to Hair Loss?

Hair follicles, like all other tissues in the body, rely on oxygen and nutrients to sustain their growth. Vitamin B12 is essential for producing red blood cells, which transport oxygen to all tissues.^[16]Ahmad, Z., Xie, M., Wu, Y., Hou, S. (2019). Effect of supplemental cyanocobalamin on the growth performance and hematological indicators of the White Pekin Ducks from hatch to day 21. Animals. 9(9). … Continue reading

When B12 levels are low, the body produces fewer red blood cells, a condition called megaloblastic anemia.^[17]Oprea, V.D., Bojinca, V.C., Balanescu, A.R., Tatu, A.L., Bojinca, M., Romila, A. (2022). Paget’s disease of bone and megaloblastic anemia in a 72-year-old patient: A case report and systematic … Continue reading Insufficient oxygen disrupts the hair growth cycle, affecting dermal papilla cell proliferation and hair follicle growth.^[18]Park, P.J., Mondal, H., Pi, B.S., Kim, S.T., Jee, J.P. (2024). The effect of oxygen supply using perfluorocarbon-based nanoemulsions on human hair growth. Journal of Materials Chemistry. 12(4). … Continue reading 

Additionally, vitamin B12 is important for methylation, a biochemical process that influences everything from DNA synthesis to gene expression, including mechanisms that might indirectly impact hair growth. Vitamin B12 acts as a cofactor in the methylation cycle, helping convert homocysteine into methionine, an amino acid that supports the production of proteins like keratin.^[19]Zhao, M., Wang, T., Wang, B., Liu, C., Li, F., Liu, L. (2022). Dietary methionine supplementation to a low-protein diet improved hair follicle development of Angora rabbits. Animal Bioscience. 36(6). … Continue reading Methionine also contributes to the activation of the Wnt/ꞵ-catenin signaling pathway, a critical mechanism in hair follicle stem cell activation and the regulation of the hair growth cycle.^[20]Franco, C.N., Noe, M.M., Albrecht, L.V. (2022). Metabolism and Endocrine Disorders: What Wnt Wrong? Frontiers in Endocrinology. 13(887037). Available at: https://doi.org/10.3389/fendo.2022.887037 

When B12 levels are reduced, methylation efficiency decreases, leading to:

Elevated homocysteine levels: High levels of homocysteine are associated with inflammation and oxidative stress, both of which can harm hair follicles and disrupt the hair growth cycle.^[21]Karmashetty, V., Acharya, J.D., Ghaskadbi, S., Goei, P. (2016). Mathematical modeling of glutathione status in type 2 diabetics with vitamin B12 deficiency. Frontiers in Cell and Developmental … Continue reading 

Reduced methionine synthesis: A deficiency in methionine may impair the Wnt/ꞵ-catenin pathway, which is already downregulated in common hair loss conditions like androgenic alopecia (AGA). This further diminishes hair follicle activity, potentially leading to hair thinning or shedding.^[22]Albrecht, L.V., Bui, M.H., De Robertis, E.M. (2019). Canonical Wnt is inhibited by targeting one-carbon metabolism through methotrexate or methionine deprivation. Proceedings of the National Academy … Continue reading 

Despite the theoretical mechanisms that connect B12 to hair health, scientific studies have not consistently demonstrated a direct correlation between low B12 levels and hair loss.^[23]Arslan, H., Gunduz, O. (2023). Micronutrient deficiencies and digital computerized phototrichogram analysis in telogen effluvium: a retrospective correlation study in a tertiary medical center. … Continue reading Blood tests in people experiencing common types of hair loss, like AGA, typically show normal B12 levels, suggesting other factors are primarily at play. 

Additionally, large-scale reviews have found no evidence that B12 supplementation improves hair loss in people who are not deficient.^[24]Almohanna, H.M., Ahmed, A.A., Tsatalis, J.P., Tosti, A. (2018). The role of vitamins and minerals in hair loss: a review. Dermatology and Therapy. 9(1). 51-70. Available at: … Continue reading  

For most people experiencing hair loss, B12 deficiency is unlikely to be a primary cause. That said, ensuring adequate B12 levels is essential for overall health, and correcting a deficiency may indirectly improve hair growth in cases where it impacts follicle function or oxygen delivery.

You can read more about the link between Vitamin B12 and hair growth here.

4. Vitamin E

How Might Vitamin E Deficiency Contribute to Hair Loss?

Vitamin E is a family of fat-soluble vitamins (much like the B vitamin family) that are split into two main groups: tocopherols and tocotrienols. It is a powerful antioxidant that helps protect the fats in our cell membranes from damage caused by harmful molecules called free radicals. These free radicals can trigger a process called lipid peroxidation, where the fats in cell membranes break down, leading to cell damage.

Research has demonstrated a link between increased lipid peroxidation and conditions like AA. In patients with AA, lipid peroxidation was found to be significantly higher than controls, indicating lower antioxidant activity in the hair follicles of those affected.^[25]Koca, R., Armutcu, F., Altinyazar, C., Gurel, A. (2005). Evaluation of lipid peroxidation, oxidant/antioxidant status, and serum nitric oxide levels in alopecia areata. Medical science monitor: … Continue reading 

Similarly, a study investigated serum and tissue levels of vitamin E in patients with psoriasis, vitiligo, and AA, finding that significantly lower levels were observed compared to control subjects (Figure 4).^[26]Ramadan, S., Tawdy, A., Hay, R.A., Rashed, L., Tawfik, D. (2013). The antioxidant role of paraoxonase 1 and vitamin E in three autoimmune diseases. Skin Pharmacology and Physiology. 26. 2-7. … Continue reading 

However, other research presents conflicting results. For example, a separate study found no significant difference in vitamin E levels between patients with alopecia areata and controls, raising questions about whether vitamin E deficiency alone is a direct driver of hair loss in these cases.^[28]Naziroglu, M., I, Kokcam. (2000). Antioxidants and lipid peroxidation status in the blood of patients with alopecia. Cell biochemistry and function. 18(3). 169-173. Available at: … Continue reading 

When it comes to AGA, a number of studies have shown an increase in oxidative stress in the scalps and hair follicles of people with AGA.^[29]Giralt, M., Cervello, I., Nogues, M.R., Puerto, A.M., Ortin, F., Argany, N., Mallol, J. (1996). Glutathione, glutathione S-transferase and reactive oxygen species of human scalp sebaceous glands in … Continue reading,^[30]Erdogan, H.K., Bulur, I., Kocaturk, E., Yildiz, B., Saracoglu, Z.N. Alatas, O. (2017). The role of oxidative stress in early-onset androgenetic alopecia. Journal of Cosmetic Dermatology. 16(4). … Continue reading However, this hasn’t been linked with low vitamin E levels.

While vitamin E deficiency might exacerbate conditions associated with oxidative stress, a direct causal link between deficiency and hair loss remains unclear. 

You can learn if vitamin E supplementation is good for your hair, whether you have a deficiency or not, here.

5. Vitamin A

How Might Vitamin A Deficiency Contribute to Hair Loss?

Vitamin A is a fat-soluble vitamin important for various biological functions, including cell growth, immune function, and vision. When it comes to hair health, vitamin A plays a dual role: it supports hair follicle function while also regulating the production of sebum, an oily substance that moisturizes the scalp. Both deficiency and excess vitamin A can disrupt these processes, potentially leading to hair loss.

Vitamin A comes in two forms: preformed vitamin A (retinoids) or provitamin A carotenoids (like beta carotene -which is converted to retinol in the body). In the scalp, retinol deficiency can lead to the development of a condition called follicular hyperkeratosis, a condition where hair follicles become clogged with keratin.^[31]Napoli, J.L. (2022). Vitamin A in skin and hair: an update. Nutrients. 14(14). 2952. Available at: https://doi.org/10.3390/nu14142952 Furthermore, low retinol levels can inhibit sebum production in the sebaceous glands, which can lead to a dry scalp and may contribute to hair loss.^[32]Suo, L., VanBuren, C., Hovland, E.D., Kedishvili, N.Y., Sundberg, J.P., Everts, H.B. (2021). Dietary vitamin A impacts refractory telogen. Frontiers in Cell and Developmental Biology. 5(9). 571474. … Continue reading 

Vitamin A deficiency is a pressing health issue in developing countries where 30-50% of children in regions such as Africa and East Asia are affected.^[33]Stevens, G.A., Bennet, J.E., Hennocq, Q., Lu, Y., De-Rgil, L.M., Rogers, L., Danaei, G., Li, G., White, R.A., Flaxman, S.R., Oehrle, S.P., Finucane, M.M., Guerrero, R., Bhutta, Z.A., Then-Paulino, … Continue reading

In contrast, vitamin A deficiency is rare in developed countries, with studies showing that less than 1% of Americans have a retinol deficiency despite a significant percentage of the population carrying a BCMO1 mutation.^[34]National Institutes of Health. (2023). Vitamin A and Carotenoids Fact Sheet for Health Professionals. NIH. Available at: … Continue reading 

This mutation impairs the conversion of beta-carotene (from plant-based foods) into retinol.^[35]van Helden, Y.G.J., Heil, S.G., van Schooten, F.J., Kramer, E., Hessei, S., Amengual, J., Ribot, J., Teerds, K., Wyss, A., Lietz, G., Bonet, M.Luisa., von Lintig, J., Godschalk, R.W.L., Keijer, J. … Continue reading Most individuals with the mutation meet their vitamin A needs through retinol-rich animal products, explaining the low prevalence of deficiency. Importantly, no evidence exists that individuals with common BCMO1 mutations experience disproportionate hair loss compared to those without the mutation.

So, should you supplement with vitamin A if you experience hair loss? Well, we wouldn’t recommend running to buy it as it is unlikely to provide hair health benefits unless a documented deficiency exists. Furthermore, evidence suggests that over-supplementation actually poses risks of hypervitaminosis A, which can itself cause hair loss. You can read more about that here.

What Are Some Practical Tips for Addressing Vitamin D Deficiencies?

• Testing: Before starting supplements, confirm any deficiencies with a healthcare professional through blood tests.

• Diet: Opt for a nutrient-rich diet to support overall hair and scalp health.

• Lifestyle: Try to minimize stress, stay hydrated, and look after your scalp. 

• Caution: Avoid megadoses of vitamins, as excess can lead to toxicity and paradoxical hair loss.

Final Thoughts

While evidence exists that some vitamin deficiencies can lead to poor hair health and subsequent loss, in many cases, this is rare and can be addressed with supplementation. However, for the general public experiencing hair loss without deficiencies, it’s unlikely that vitamin supplementation will solve anything. In fact, excessive reliance on supplements without medical guidance may not yield benefits and could even harm overall hair health.