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B-complex vitamins

A sensible insurance policy if your diet is genuinely short — and close to useless if it is not.

Reviewed by Bodil Isaksson, Licensed Biomedical Scientist (Sweden)Last reviewed July 2026Supplement guide

SupplementsHair, skin & nailsDeficiency-only

The B vitamins are the follicle’s cofactors: B12, folate, riboflavin and B6 all feed the rapid cell division and keratin-building that growing hair depends on, and several are tied to skin health too. That makes “B-complex for hair” sound compelling — but the evidence tells a narrower story than the label. This is a deficiency story, not a more-is-better one.

Key takeaways

  • B12, folate and riboflavin deficiencies are linked to hair and skin changes; correcting a real shortfall helps.1
  • In people who are already replete, there is little evidence that extra B vitamins do anything for hair.
  • They are water-soluble, so surplus is mostly excreted — but not risk-free: niacin causes flushing, and chronically high-dose B6 can cause reversible nerve damage.
  • For most people a plain multivitamin or a better diet covers the same ground as a dedicated B-complex.

What the B vitamins actually do here

Riboflavin (B2), B12, folate (B9) and B6 act as cofactors for enzymes that let the hair bulb divide and keratinise at speed, and for the methylation and red-cell production that keep the scalp supplied with oxygen and nutrients. Biotin (B7) belongs to the same family — covered on its own page, with its important lab-test caveat. When any of these run genuinely low, hair and skin are among the first tissues to show it, because they are expensive to maintain and easy for the body to deprioritise.

The deficiency angle

This is where B vitamins earn their place. B12 and folate deficiency — common in vegans, older adults, people on metformin or acid-blockers, and anyone with malabsorption — is associated with hair changes and premature greying, and correcting it is worthwhile for far more than hair.1 Riboflavin deficiency shows up as cracked lips and skin. If you are in a risk group, checking and correcting these is sensible medicine.

If you already eat well

Here the honest answer is unglamorous: topping up B vitamins you already have in adequate supply does not appear to grow hair or improve skin. Water-solubility means most of the excess ends up in your urine. It is not free of downside either — sustained high-dose B6 (often above ~100 mg/day for long periods) can cause a peripheral neuropathy that is usually but not always reversible, so avoid loading up “just in case”.

A practical take

Eat B-rich foods (eggs, dairy, meat or fortified foods, leafy greens, legumes); if you are in a deficiency risk group, test and correct specifically — a targeted B12 rather than a scattergun megadose. A standard multivitamin is a reasonable floor. A premium “hair B-complex” on top of an already-good diet is mostly buying expensive urine.

Bottom line: B vitamins matter for hair and skin through deficiency correction, not as a booster. Fix a real shortfall (usually B12/folate); if you are replete, a multivitamin is plenty.

References

Adult research summary for education, not a prescription. These are food supplements, not treatments for disease.

  1. Almohanna HM, Ahmed AA, Tsatalis JP, Tosti A. The role of vitamins and minerals in hair loss: a review. Dermatol Ther (Heidelb) 2019;9(1):51–70. pubmed.ncbi.nlm.nih.gov

This article summarises nutrition science for education. It is not a substitute for individual medical advice; consult a professional before starting a supplement, in pregnancy, or alongside medication.