Hair Growth Vitamins and Supplements

Vitamin D is a fat-soluble vitamin made in the skin. When your skin comes into contact with the sun’s UV light, it becomes activated and travels to the liver and kidneys. It then undergoes further chemical reactions to produce its final active form. This nutrient helps control calcium and phosphorous levels in the blood, regulates the immune system, and exerts anti-inflammatory properties. (11) 

Hair follicle cells contain receptors for vitamin D, making it important in hair growth. People with genetic mutation of this receptor, like those with type II rickets, have very little to no hair growth on their bodies. (12)

Evidence suggests that vitamin D deficiency is linked to alopecia areata, an autoimmune form of hair loss. A meta-analysis found that the average vitamin D level in alopecia areata patients is significantly lower compared to people without this type of hair loss. Additionally, alopecia areata patients were more likely to be vitamin D deficient. (13) 

This study did not find a significant link between vitamin D levels and the severity of hair loss. However, a more recent test in 45 adults found a negative correlation between vitamin D levels and the severity of alopecia areata. (14) Another study showed the same results in 50 individuals with androgenic alopecia (pattern hair loss), with a correlation between vitamin D deficiency and the severity of the disease in these patients, as well. (45)

The link between vitamin D and hair health is strong. However, studies examining whether supplemental vitamin D can promote hair growth in those who are not deficient are lacking. Although many hair growth supplements contain vitamin D, more large-scale studies need to be undertaken before this question can be answered.

B-Complex vitamins are involved in cell metabolism and development, energy production, and cell signaling. These eight B vitamins are:

• Thiamine (Vitamin B1)
• Riboflavin (Vitamin B2)
• Niacin (Vitamin B3)
• Pantothenic Acid (Vitamin B5)
• Pyridoxine (Vitamin B6)
• Biotin (Vitamin B7)
• Folate (Vitamin B9)
• Cobalamin (Vitamin B12)

Biotin is the only vitamin in this list that the body can produce on its own. The other B-complex vitamins can be easily obtained through eating a balanced diet. 

Of the vitamins listed, only B2, B7, B9, and B12 are associated with hair loss. (9) Deficiencies of these vitamins are rare in the western world.

Riboflavin (B2) plays an essential role in energy production, fat metabolism, and cellular function. Riboflavin is stored in small amounts in the heart, kidneys, and liver, and while deficiency is very rare in the western world, not getting enough riboflavin is known to cause hair loss. (15)

Biotin (B7) deficiency can be genetic or may occur due to chronic alcoholism, pregnancy, use of certain antibiotics, malnutrition, or consumption of raw eggs. Signs of biotin deficiency include brittle nails, hair loss, and skin issues. 

However, studies using biotin supplementation as a treatment for deficiency don’t usually show significant hair growth. One small study showed that biotin supplementation improved growth in 18 patients with hair loss, whether the cause was genetic or not. (16) If you choose to take biotin supplements, be aware that biotin is known to interfere with medical laboratory tests such as thyroid levels or even troponin, which is used to detect if a person has suffered a heart attack. (9)

Both folate, vitamin B12, and hair growth are linked because these B-vitamins are associated with nucleic acid production, the building blocks of DNA. They play a significant role in hair follicles, which are constantly undergoing growth, shedding, and regrowth.

Both folate and vitamin B12 deficiency can cause anemia and skin, hair, and nail changes. A reasonable assumption, then, would be that these vitamins would be found in lower levels in patients suffering from hair loss. Interestingly, studies investigating levels of these vitamins in patients with alopecia areata found no significant differences compared to individuals without this condition. (17,18)

Vitamins C and E are also antioxidants. They help prevent the oxidation of fatty acids and damage caused by unstable molecules called free radicals. Both of these essential nutrients must be obtained from the foods you consume.

Also known as ascorbic acid, vitamin C also plays a role in collagen production and iron absorption, assisting this mineral move across the intestinal wall. For this reason, vitamin C is indirectly involved in hair loss due to iron deficiency. Body hair changes can be related to vitamin C deficiency, but no studies link low vitamin C levels to hair loss. (9)

Vitamin E, also known as tocopherol, helps modulate the immune system through its antioxidant function. (19) Like vitamin C, it helps protect the body against damage caused by free radicals. 

It can be theorized that autoimmune conditions such as alopecia areata, which are dependent on physiological stressors, among other things, may be related to low levels of antioxidants like vitamin E. The evidence for this is conflicting, with studies showing opposite results. (20,21) 

One small study gave people a daily dose of 100 milligrams of vitamin E for hair loss. The study participants experienced increased hair counts (by 34.5 percent) compared to those receiving placebo (0.1 percent). (22)

Other antioxidants include beta-carotene and lycopene. Lycopene gives red and pink fruits like watermelon, tomatoes, and grapefruit their characteristic colors. Similarly, beta-carotene is a pigment found in yellow and orange fruits and vegetables. Once in the body, this antioxidant gets converted to vitamin A, an essential nutrient for cell metabolism and development.

These powerful antioxidants have been found to reduce the risk of certain cancers, heart disease, stroke, and even sunburn. (23) However, there is no definitive link between these antioxidants and the promotion of hair growth.

Multivitamins can help correct underlying vitamin deficiencies. However, if you’re wondering which vitamins are good for hair, no specific vitamin has been found to conclusively promote hair growth or correct hair loss. Taking a multivitamin for hair growth may not be beneficial, and can even be unsafe in some cases. Over-supplementation of vitamins A, C, E, zinc, iron, selenium, vitamin B6, or vitamin B12 can cause adverse effects. (24) 

All vitamins have a maximum recommended daily intake. However, many supplements far exceed these recommended amounts. 

Multivitamins and nutraceuticals are classified under the same category as foods and don’t undergo the same regulation that medications do. For example, the daily recommended intake of vitamin A is 2.4 micrograms per day, but OrionPharma’s Beauty Vitamins contain 20 micrograms per dose (2 pills), 833 percent of your recommended daily intake! 

Magnesium is a cofactor that the body utilizes to help enzymes do their jobs. These enzymes are part of hundreds of different biochemical reactions in the body, including protein synthesis, blood sugar control, energy production, nerve function, and blood pressure management. (46) Due to its involvement in so many bodily functions, magnesium is often added to supplements to promote the growth of new hair follicles. However, there’s little evidence to support this claim.

A study investigating magnesium levels in patients suffering from alopecia areata, an autoimmune form of hair loss, found that levels of this mineral are not significantly lower than those found in healthy patients. (26) Magnesium’s utility in causing or promoting hair growth suffers from a lack of scientific backing, yet it continues to be added in many supplements advertising hair growth. (10)

Zinc is a mineral essential for the function of hundreds of enzymes. It’s involved in immune function, gene expression, and cell signaling pathways. These functions are crucial for healthy hair growth, and low zinc levels may cause brittle hair and hair loss. (10) Zinc deficiency can occur due to malnutrition, alcoholism, pregnancy, cancers, and kidney or liver problems. It can even happen to vegetarians, as zinc is not easily absorbed when obtained from vegetables rather than meat. (27)

Zinc can correct hair loss in patients with telogen effluvium (stress-induced hair loss) and zinc deficiency. (28) It’s also helped patients suffering from both alopecia areata (autoimmune hair loss) and zinc deficiency. (29) 

A study of over 300 patients found lower zinc concentrations in people with varying types of hair loss compared to 30 healthy individuals. (30) However, it’s unclear how zinc supplementation can benefit those without an underlying deficiency. Over supplementation can result in zinc toxicity, which can cause vomiting, diarrhea, and pain. 

Iron is a critical factor in the formation of healthy red blood cells and functional hemoglobin, which allows blood to transport oxygen throughout the body effectively. It is also involved in DNA synthesis. Iron deficiency is often found in women with hair loss, but it’s unclear if there’s a causal relationship. (31) 

A 2017 review examined five studies examining the link between iron deficiency and alopecia areata (autoimmune hair loss). None of the studies concluded a significant relationship. (32) Other groups attempting to study this link have been found to differ in their design, patient populations, and in their definition of iron deficiency. (10)

At this time, there are no studies that show a definitive link between iron deficiency and hair loss. Yet, a 2003 study did show that levels of ferritin (a protein that indirectly reflects the body’s total iron stores) were significantly lower in women with alopecia areata and with pattern hair loss. (47)

It is very important to monitor iron intake, especially when taking supplements. Iron over-supplementation can result in a condition known as secondary hemochromatosis, or iron overload, which can cause liver, heart problems, and diabetes.

Copper partners with iron to help the body form blood cells. It supports the health of the immune system, blood vessels, bones, and nerves. Copper’s role in hair growth is not entirely understood, but one 2007 study found that copper peptides (copper in combination with amino acids) stimulated hair follicle growth in humans. (33) Larger scale studies are needed — and with copper in mind specifically, instead of multiple ingredients — to determine this mineral’s efficacy in promoting hair growth.

A 2013 study evaluated the levels of zinc and copper in people experiencing autoimmune, stress-related, and pattern hair loss. They found that these people had lower zinc levels than healthy individuals, but copper levels were not significantly different. (30)

Selenium is involved in producing many proteins and is necessary for the synthesis of antioxidants in the body. Lately, it’s made headlines claiming a wide range of health benefits, including hair growth, preventing cancers, immune function, and more. 

As with many other nutrients in supplements, research on selenium contributing to hair growth is lacking. However, a clinical trial in ovarian cancer patients undergoing chemotherapy found that patients taking selenium supplements experienced less hair loss than those who did not. (34)

The lack of evidence for selenium supplementation has not stopped hair growth supplements from advertising it on their bottles. However, too much selenium can cause nausea, vomiting, skin blisters, irritability, fatigue, and even hair loss. 

In 2008, a selenium toxicity outbreak occurred in the United States due to a formulation error in a liquid nutritional supplement. The selenium concentration was 200 times greater than what was advertised on the bottle, causing severe hair loss in most patients affected. (35)

Many supplements advertise that they aid hair growth. However, they can sometimes contain dangerous levels of vitamins, minerals, or other nutraceuticals that can lead to toxicity, including hair loss. (9,10,36) 

Pay attention to the nutritional information on these bottles. Supplements that contain higher than recommended amounts of vitamin A, vitamin E, selenium, iron, and zinc can actually cause hair loss. (9,10) Too much of a good thing can be bad, something that certainly applies to essential nutrients.

It is not known if supplementation of amino acids can lead to hair loss, but over-supplementation of certain compounds can cause health issues. For example, the amino acid lysine is believed to be involved in iron absorption. Too much of this amino acid can cause iron overload, resulting in liver and heart issues. (9)

Many of the additives in multivitamins can also cause serious reactions with medications. Ginseng, for example, is sometimes added into supplements for hair loss because of its antioxidant, DHT-blocking, and anti-inflammatory properties. However, this plant can interact with warfarin, a powerful blood thinner. It can reduce the drug’s efficacy, making blood more likely to clot in patients who need their blood to be thin. (37) As it stands, hair loss vitamins that work are difficult to establish, and more research is needed before it can be confidently reported.

In excessive amounts, certain vitamins may lead to hair shedding or thinning. For example, vitamin A can cause hair loss when levels are high. (10) 

Vitamin E is a very important antioxidant, and deficiencies can result in anemia, neurologic problems, and skin issues. Too much vitamin E can decrease thyroid hormone levels, which are essential for hair growth, and cause hair loss. This was seen in healthy volunteers who took 600 IU (international units) — about 30 times the recommended vitamin E intake — per day for 28 days. These volunteers were found to have significantly decreased thyroid hormone levels, a symptom of which is hair loss. (38)

Minerals are essential for bodily functions, but their role in promoting hair growth is yet to be determined. Deficiencies in essential minerals such as zinc and iron can cause hair loss. However, the same can be said for the over-consumption of minerals, like selenium. Concentrations of these minerals need to be in a moderate “sweet spot” to work. 

The levels of minerals in supplements advertised for hair growth are not regulated. Over-supplementation can occur, which may lead to hair loss. (39)