The short answer
Low vitamin B12 can contribute to hair shedding, though the evidence is less strong than for iron. It usually causes thinning all over the scalp rather than patches, along with tiredness and other symptoms. A blood test through your GP shows whether you’re low, and it’s worth checking iron, thyroid and vitamin D at the same time, as low B12 is rarely the only cause.
How does low B12 affect hair?
Vitamin B12 is needed to make red blood cells and to make new cells, including the fast-dividing cells in hair follicles. When levels are low, the body prioritises essential organs, and more hairs can move into the resting phase and shed. Telogen effluvium.
Signs of B12 deficiency
- Tiredness and lack of energy, breathlessness or looking pale
- Pins and needles or numbness in your hands or feet
- A sore, red tongue or mouth ulcers
- Problems with memory, concentration or mood
- Hair shedding from all over the scalp
Pins and needles, numbness or problems with balance need seeing promptly, as long-term B12 deficiency can affect the nerves.
Who is more likely to be low?
- Vegans, and vegetarians who eat few eggs or dairy foods, as B12 comes mainly from animal foods
- People with pernicious anaemia, an autoimmune condition that stops B12 being absorbed
- People with coeliac disease, Crohn’s disease or stomach surgery
- People taking some long-term medicines, such as metformin or stomach acid medicines
- Older people, who absorb B12 less well
Should I take B12 for hair loss?
Not without a blood test. Extra B12 won’t help your hair if your levels are normal. If you’re low, your GP will find out why and treat it, with tablets or injections depending on the cause. Folic acid on its own can hide the anaemia caused by low B12 while the deficiency carries on, which is another reason to test first. Blood tests for hair loss.
Once your levels are put right, shedding usually settles over a few months. Iron and hair loss · Vitamins for hair growth.
If something isn’t right with your hair or scalp, I’ll take your history, examine your hair and scalp closely and give you a written plan. What happens at a consultation.
Questions
Does B12 deficiency cause hair loss?
It can contribute to shedding all over the scalp, usually alongside tiredness or other symptoms. It’s rarely the only cause.
Will my hair grow back after B12 deficiency?
Usually, yes. The follicles aren’t damaged, so once your levels are back to normal, shedding settles and hair regrows over several months.
What does B12 hair loss look like?
General thinning and more hair than usual on your brush and in the shower, from all over the head, rather than bald patches.
Can pernicious anaemia cause hair loss?
Yes. Pernicious anaemia stops B12 being absorbed, and the deficiency can cause shedding. It’s treated by your GP, usually with injections.