Vitamins and other micronutrients are not only essential for a healthy body and mind but also important for healthy hair growth. When our vitamin levels get dangerously low, it can impact hair growth and even lead to hair shedding. That’s why lots of people worry about which vitamin deficiencies cause hair loss.
It should be noted that vitamin deficiencies are extremely rare in developed countries. Many people have vitamin inadequacies where they don’t meet the recommended micronutrient level however, very few people have clinical deficiencies.
Dr. Michael May explains what’s meant by a nutritional deficiency:
“A nutritional deficiency happens when your vitamin or mineral levels are so low that they cause observable clinical symptoms. This could be anything from bone fractures to vision problems, depending on the vitamin in question.”
Hair loss is an observable clinical symptom in some cases. So which vitamin deficiencies can cause hair loss? In this article, you’ll learn:
Male pattern baldness 
Female pattern hair loss 
Alopecia areata 
Telogen effluvium [2-5].
Iron is a core component of haemoglobin, a red blood cell protein that carries oxygen around the body. Iron deficiency can reduce the amount of haemoglobin in the blood. This is known as iron deficiency anemia.
When you’re anemic, your body prioritises oxygen delivery to your essential organs. That means your hair follicles don’t always get the oxygen and nutrients they need to produce healthy hair.
Iron is also needed to produce collagen. Collagen is made up of amino acids that are essential for keratin production. Keratin is the protein that makes up the majority of the hair shaft, so it’s essential for keeping your hair healthy.
Alopecia areata [8-10]
Telogen effluvium 
Hair follicles contain vitamin D receptors. When you have healthy vitamin D levels, these receptors help regulate your hair growth cycle and create healthy hair follicles. In fact, studies show that not having vitamin D receptors can lead to alopecia .
Most people do have these receptors. However, if you don’t have enough vitamin D, they may not work as they should. This can make your hair enter the shedding (or telogen) phase prematurely, creating the appearance of thinning hair.
Vitamin D also plays an important role in regulating your immune system . Low vitamin D levels can alert inflammatory cytokines (proteins that give signals to your immune system) and provoke an autoimmune response. This leads to conditions like alopecia areata (a condition where patchy hair loss occurs) and causes inflammation around your follicles.
Healthy hair follicle cells grow and divide over time. This process is called cell proliferation, and your body needs a healthy zinc supply to make this type of cell growth happen. Cell proliferation encourages hair growth and repair. Zinc is also required for other cell processes, such as creating new proteins that promote hair growth and aid hair follicle recovery.
Zinc can also stop hair from entering the final catagen phase of growth . As a result, it’s been linked with several types of hair loss.
Without biotin, you may not be able to produce enough keratin. As keratin is the core hair protein, this can cause your hair to feel dry and brittle, and may even lead to hair loss.
Alopecia areata 
Vitamin E is an essential antioxidant. Antioxidants neutralise free radicals that damage follicle cells. Free radicals are highly unstable chemical entities that react with other molecules in your body, leading to oxidative stress which can facilitate the development of alopecia .
Vitamin E is the only micronutrient where dietary supplements are proven to have a positive effect on hair growth in patients, even if you don’t have a nutritional deficiency .
Folate, also known as vitamin B9, is needed to make and repair DNA molecules. Ageing, defective, and damaged DNA is known to cause hair problems, including alopecia . So a folate deficiency could damage your hair and even prevent healthy hair growth.
Lack of folate can also cause folate deficiency anaemia. People with this condition produce abnormally large red blood cells that can’t carry oxygen and nutrients around the body in the same way that healthy red blood cells can. So your follicles miss out on nutrients they need for hair growth.
There’s not much evidence that taking folic acid will help hair growth unless you have an active deficiency.
Vitamin A deficiency has been linked with alopecia areata. Vitamin A regulates T-cell activity, helping the immune system function properly .
However, excessive vitamin A can have a toxic effect on the body. There’s a lot of evidence that too much vitamin A actually causes hair loss . Therefore, it’s not recommended to take a vitamin A supplement as a hair loss treatment unless your GP has verified its safety.
A lack of riboflavin, or vitamin B2, may lead to generalised hair loss . People with a riboflavin deficiency find it more difficult to properly digest proteins (as well as carbohydrates and fats), which can lead to unhealthy hair .
Riboflavin deficiency may also lead to reduced protein production, thanks to lower levels of haemoglobin in the blood. It can also reduce the metabolism of other B vitamins like folate [27-28].
There’s some conflicting evidence for whether a vitamin B12 deficiency causes hair loss. One research paper claims changes in vitamin B12 levels can modify the progression of alopecia areata .
Another found no difference between the levels of vitamin B12 in patients with and without alopecia areata . Any link between vitamin B12 levels and alopecia areata may be due to the autoimmune nature of pernicious anaemia, which is the main cause of vitamin B12 deficiency in the UK.
Vitamin B12 deficiency has also been linked with hair greying and whitening as early as childhood .
There’s not much evidence to link vitamin C deficiency with hair loss. However, your body needs vitamin C to absorb iron. Therefore, if you don’t get enough vitamin C, you could develop an iron deficiency that impacts your hair health .
Vitamin C is also essential for collagen production, which helps hair stay strong and shiny .
While some vitamin deficiencies have noticeable symptoms, you’ll need a blood test to confirm whether you have a true vitamin deficiency.
Symptoms of a nutritional deficiency include:
Remember that most people in the UK don’t have nutritional deficiencies. So even if you see some of these symptoms, they may not be related to a lack of vitamins.
The best way to prevent vitamins and minerals deficiencies is to maintain a healthy lifestyle and healthy diet. This includes:
If you think you might have a vitamin deficiency, you should speak to your GP. They can arrange free blood tests to determine whether or not you have a vitamin deficiency.
When your deficiency has been diagnosed, your doctor can help you find the right treatment. This will probably involve vitamin supplements or, in more severe cases, a vitamin IV drip.
Unless you have a vitamin deficiency, supplements aren’t usually recommended to treat hair loss. That’s because there’s not much evidence that vitamin supplements promote hair growth.
In the UK, vitamin deficiency is an unlikely cause of hair loss. Even if low vitamin levels are contributing to your condition, they’re probably not the only cause. That’s why it’s important to get hair loss checked out by a trichologist as well as your GP.
Trichologists are hair loss specialists who can help diagnose your condition and create a treatment plan for hair regrowth. If you’re worried about losing hair, book a consultation with our trichology team to diagnose and understand your condition.
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