The Best Vitamins for Hair Growth (and Which Ones Actually Matter)

The vitamins and minerals that matter most for hair growth are iron, vitamin D, zinc, the B vitamins (including biotin, B12 and folate), and vitamins C and E. They help most when you're actually low in one. If your levels are already normal, there's little evidence that taking more grows extra hair, and too much of some, such as vitamin A and selenium, can make shedding worse.

This guide covers which nutrients hair needs, how to tell whether you're low, whether hair growth supplements work, and how to choose one.

Key fact: The most useful step is often a blood test. Low iron stores, vitamin D or B12 are common, easy to check, and worth correcting for your overall health as well as your hair.

Which Vitamins Are Best for Hair Growth?

The nutrients with the strongest link to healthy hair growth are the ones whose deficiency is linked to hair loss. Here's what each does and when it's worth paying attention.

What Vitamin Am I Lacking If My Hair Is Thinning?

Low iron stores and low vitamin D are the shortfalls most often found in people with thinning hair, followed by zinc and vitamin B12. You can't tell which one from your hair alone. Ask your doctor about a blood test, especially if you also feel tired, have heavy periods, or follow a restricted diet. Zinc and hair loss and iron deficiency and hair loss.

Is Biotin or B12 Better for Hair?

Neither is "better". They do different jobs, and each only helps if you're low. B12 deficiency is fairly common, especially if you eat few animal foods or are older. Biotin deficiency is rare, which is why biotin on its own often disappoints people with normal levels. How long biotin takes to work, how much biotin to take and vitamin B12 for hair.

One practical caution: high doses of biotin can interfere with some blood tests. If you take it, tell your doctor before any blood work.

Do Hair Growth Supplements Work?

They can help if they fill a gap in your diet. A good supplement covers the nutrients most often low, in sensible amounts, so you're not relying on one vitamin. What a supplement can't do is override genetics or hormones. Pattern hair loss, for example, has its own causes and its own options. How to stop hair loss: what actually works.

Give any supplement at least three months. Hair grows slowly, and new growth takes time to show.

What Is the "Big 3" for Hair Loss?

"The big 3" is online shorthand, mostly in men's forums, for minoxidil, finasteride and ketoconazole shampoo, used together for pattern hair loss. Finasteride needs a prescription and isn't suitable for everyone, so it's a conversation for your doctor. Vitamins aren't part of the big 3, but correcting a deficiency can matter alongside any treatment.

How to Choose a Hair Vitamin

• Look for the nutrients that matter: vitamin D, zinc, B12, folate and biotin, rather than a single megadose.
• Check the doses. Avoid very high vitamin A or selenium unless your doctor recommends them. Vitamin A: too little, too much and selenium and hair.
• Check for iron separately. Many hair supplements, including ours, don't contain iron. If a blood test shows you're low, your doctor will advise on iron.
• Be patient. Judge it after three to six months, not three weeks.

What the Research Shows

A 2019 review of vitamins and minerals in hair loss (Almohanna et al.) looked at vitamins A, B, C, D and E, iron, selenium and zinc. It describes them as important, though not fully understood, players in the hair follicle cycle, and calls deficiency a possibly modifiable risk factor for hair loss. The authors say large placebo-controlled trials are still needed to show which supplements help.

A review of biotin for hair loss (Patel et al., 2017) found 18 reported cases where biotin improved hair or nails. In every case the person had an underlying cause, such as an inherited or acquired biotin deficiency. The authors concluded there isn't enough evidence to recommend biotin to healthy people.

A review of diet and hair loss (Guo and Katta, 2017) recommends screening people with hair loss for risk factors for deficiency, and correcting any deficiency found. It notes that there's little research on supplements for people who aren't deficient, and that some supplements can worsen hair loss or be toxic in excess.

Where Hair Revival Supplements Fit

FullyVital's Hair Revival Supplements combine the nutrients that matter for hair, including vitamin D3, vitamin B12 (as methylcobalamin), folate, biotin, zinc, selenium, copper and vitamins C and E, with botanicals such as saw palmetto, pumpkin seed oil, ashwagandha and curcumin. They're designed to support healthy hair growth from the inside as a daily all-in-one, not to treat a deficiency. They don't contain iron. Pair them with the Hair Revival Serum for scalp support, or get both in the Hair Revival Kit 30-Day.

Diet matters too. See protein-rich foods for hair growth.

For biotin on its own, see our guide to biotin for hair growth.

Frequently Asked Questions

What is the best vitamin for hair growth?

There isn't one best vitamin. Iron, vitamin D, zinc and B12 matter most, and the one that helps you most is the one you're low in. A blood test is the only way to know.

How can I increase my hair growth and thickness?

Correct any deficiency, eat enough protein, look after your scalp, and be patient. If thinning is getting worse, see a doctor or dermatologist to find the cause.

Do hair, skin and nail vitamins really work?

They can help if your diet is missing something. There's little evidence that they add growth when your levels are already normal.

Can taking too many vitamins cause hair loss?

Yes. Too much vitamin A or selenium is linked to hair loss. Stick to sensible doses unless your doctor advises otherwise.

How long do hair vitamins take to work?

At least three months, and often longer. New growth starts at the root and takes time to become visible.