Does vitamin B12 affect hair?

The skin on the human head contains approximately 100,000 hair follicles, 90% of which are constantly in the so-called anagen phase, i.e. the active phase of hair growth, when the hair follicle cells multiply intensively, producing new hair. In order to effectively produce healthy hair, the anagen phase requires the supply of essential nutrients such as amino acids, minerals and vitamins to the follicle.

1. Vitamin B12 for hair
2. A few words about cobalamin
3. Vitamin B12 in hair production
4. How hair suffers when it is lacking...
5. Diet for hair

Vitamin B12 for hair

Vitamins are key components of a hair care diet, and vitamin B12 is one of the most important vitamins in such a diet.

A few words about cobalamin

Vitamin B12, known technically as cobalamin, belongs to the B vitamins, i.e. water-soluble, essential micronutrients that act as coenzymes activating enzymes, i.e. proteins that catalyse vital biochemical processes in the cells of the human body.

Cobalamin is found in food in several molecular variants – as cyanocobalamin, methylcobalamin, deoxyadenosylcobalamin and hydroxycobalamin. However, only methylcobalamin and deoxyadenosylcobalamin are actual coenzymes that activate enzymes, while the other molecules only become active after being converted into these two basic forms.

Vitamin B12 in hair production

Vitamin B12 is a coenzyme of the methionine synthase enzyme and is therefore responsible for the synthesis of nearly 100 biological molecules, including DNA and RNA nucleic acids, and through them, a huge number of proteins. The synthesis of nucleic acids is also a fundamental process determining the phenomenon of cell reproduction.

It is precisely the involvement of vitamin B12 in the production of nucleic acids that clearly indicates that it must play a leading role in the vital functions of hair follicles in the anagen phase, when cells reproduce intensively and produce a large amount of proteins that make up to 95% of the hair's volume.

It is therefore not surprising that, in addition to other characteristic ailments, one of the symptoms of vitamin B12 deficiency is hair thinning. Low vitamin B12 levels also contribute to brittleness and premature greying of the hair.

How hair suffers when it is lacking...

Study 1

In a clinical control study involving 52 patients under the age of 20 with premature greying, the authors assessed and compared the levels of biotin, folic acid and vitamin B12 with a control group of non-greying individuals. The results showed that prematurely greying individuals had a deficiency of vitamin B12 and folic acid and lower levels of biotin, but no significant deficiency of the latter vitamin.

Study 2

Another study assessed folic acid and vitamin B12 levels in 115 patients with acute and chronic telogen effluvium resulting from a hair growth cycle disorder. In this case, the results showed that some of the subjects had a vitamin B12 deficiency, but none of the patients had a folic acid deficiency.

Study 3

Another study of the relationship between telogen effluvium and vitamin B12 showed that deficiency of this vitamin is much more common in people affected by this condition than in a control group of healthy people without hair loss.

Study 4

In yet another study, a significant reduction in the average vitamin B12 level was found in a group of generally healthy, non-vegan women with androgenic (male-pattern) alopecia.

Diet for hair

The authors of the latest study therefore emphasised that this concerns non-vegan women, as vitamin B12 is only found in sufficient quantities in animal products. The main sources of vitamin B12 in our diet are therefore meat products, fish and eggs, as well as milk and dairy products.

This is why omnivores consume an average of over 7 mcg of vitamin B12 in their daily diet, while vegans consume less than 0.5 mcg. However, a healthy adult needs to consume approximately 6 mcg of this vitamin per day to prevent the onset of deficiency symptoms.

So if hair problems are close to our hearts, we should ensure that our daily diet contains sufficient amounts of vitamin B12. 

Sources:

• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5514791/
• https://jddonline.com/articles/vitamin-and-mineral-deficiencies-in-patients-with-telogen-effluvium-a-retrospective-cross-sectional-S1545961616P1235X/
• https://journals.lww.com/jdds/fulltext/2022/26020/serum_vitamin_b12_in_chronic_telogen_effluvium.2.aspx
• https://academic.oup.com/ced/article-abstract/15/4/277/6628926?redirectedFrom=fulltext