Can Lack of B12 Cause Hair Loss

Can Lack of B12 Cause Hair Loss?

Yes, a vitamin B12 deficiency can cause hair loss in some people. B12 plays a key role in the production of red blood cells, DNA synthesis, and the proper functioning of the nervous system. It also supports the health of rapidly dividing cells, including the cells found in hair follicles. When B12 levels drop too low, the body prioritises essential functions—often at the expense of non-essential processes like hair growth.

Hair loss caused by B12 deficiency is typically diffuse, meaning it occurs across the entire scalp rather than in patches or specific patterns. This kind of thinning often develops gradually, but it can sometimes accelerate if the deficiency becomes more severe. If left untreated, it may contribute to ongoing hair shedding and slower regrowth.

Why B12 Matters for Hair Health

Healthy hair growth depends on a constant supply of oxygen and nutrients delivered to the follicles through the blood. B12 is essential in helping the body produce red blood cells, which carry oxygen. When B12 is lacking, oxygen supply to the scalp can be reduced, affecting the ability of hair follicles to maintain strong, healthy growth.

In addition, B12 helps support energy production at the cellular level, including the energy required by hair matrix cells—the cells responsible for generating new hair shafts. Without adequate B12, these cells may slow down or stop producing hair altogether.

Signs You Might Be Deficient

B12 deficiency can cause a wide range of symptoms beyond hair thinning. Common signs include fatigue, weakness, brain fog, pale skin, dizziness, numbness or tingling in the hands and feet, and mood changes such as low mood or irritability. In some cases, individuals may also experience brittle nails or dry, thinning hair alongside these symptoms.

Hair loss due to B12 deficiency is often reversible, especially if caught early. Once B12 levels are restored—through dietary changes or supplementation—hair growth usually begins to normalise over the following months. However, recovery can take time, and in some cases, not all hair is regained if the deficiency has been long-term.

What Causes Low B12?

There are several reasons why someone may become deficient in vitamin B12. The most common cause is diet, particularly in people who follow a vegan or strict vegetarian diet, as B12 is found almost exclusively in animal products. Conditions that affect digestion, such as coeliac disease, Crohn’s disease or low stomach acid, can also impair the absorption of B12. Some medications, including metformin and proton pump inhibitors, may interfere with B12 levels as well.

Older adults are also more prone to deficiency, partly because the body becomes less efficient at absorbing B12 with age. Pernicious anaemia, an autoimmune condition, can cause long-term B12 deficiency by preventing the body from absorbing it properly.

What to Do If You Suspect B12-Related Hair Loss

If you’re experiencing hair thinning and suspect a vitamin deficiency, the first step is to see a GP. A simple blood test can check your B12 levels and rule out other causes like iron deficiency, thyroid problems, or hormone imbalances. If B12 deficiency is confirmed, treatment may involve dietary adjustments, oral supplements, or B12 injections—especially if absorption is an issue.

In the meantime, supporting your overall hair health through a balanced diet, stress management, and proper scalp care can help reduce further shedding. While supplements can help, it’s important to avoid self-diagnosing or over-supplementing without medical advice, as excessive B12 intake is unnecessary for most people and won’t speed up recovery.

Final Word

Lack of vitamin B12 can absolutely contribute to hair loss, especially when levels are low enough to affect red blood cell production and oxygen delivery to the scalp. The good news is that this form of hair loss is often reversible with the right treatment. If you're noticing excessive shedding alongside fatigue or other symptoms, a medical check-up is essential. With early detection and proper support, most people can restore both their B12 levels and their hair health.