Hair loss is a normal part of life. We shed anywhere from 50 to 100 hairs per day, and fluctuations in seasons, cortisol levels, or even changes in diet can temporarily increase that number. But when hair loss feels excessive or persistent, it might be time to investigate further. Often, the first step involves looking inward—specifically at your body’s nutritional health.

"Hair loss can often be an indicator of an underlying issue within the body, such as a vitamin or mineral deficiency," explains Anabel Kingsley, Consultant Trichologist and Brand President at Philip Kingsley. "Hair is incredibly sensitive to changes in your body’s health because it’s non-essential tissue. When your body is lacking in nutrients, hair is often the first thing to be affected."

Related article: Exclusive: A Day With Celebrity Hairstylist Kim Robinson At His Newly-Renovated Flagship Salon

If you’re concerned about thinning or excessive shedding, consulting with a healthcare professional and getting a blood test is key. One of the most common culprits for unexplained hair loss? Vitamin deficiency.

The good news is that, in many cases, addressing these deficiencies through diet or supplementation can make a significant difference. But how do you know which vitamins to focus on? We’ve spoken to Kingsley and Dr Margo Gkini, Consultant Dermatologist and hair loss expert, to uncover the key vitamins linked to hair loss—and how to restore balance.

Which vitamin deficiency causes hair loss?

"The vitamins and minerals an individual needs for healthy hair growth will vary from one person to another, influenced by factors such as age, sex, diet, and exercise," explains Kingsley. "Iron, vitamin B12, zinc, vitamin D, and biotin are all known to be important for hair health." Here’s what you need to know about each one.

Iron and Ferritin (stored iron)

"Iron and ferritin deficiency are some of the most common causes of excessive daily hair shedding in women," says Kingsley. "Iron plays a key role in hair growth as it aids in the production of red blood cells, which carry oxygen around the body to all our tissues and organs, including our hair follicles."

Low levels of ferritin (stored iron) are a frequent cause of Telogen Effluvium, a type of hair shedding, especially in menstruating women and vegetarians or vegans. Symptoms of iron deficiency can include fatigue, low energy, skin pallor, and of course, hair loss.

"Supplementation can be beneficial, whether through dietary changes or oral iron supplements, which typically need to be taken for three to six months before levels are reassessed," says Dr Gkini. "For individuals with severely low iron, iron injections may provide quicker results." If you’re concerned, speak to your GP about getting your levels checked.

Vitamin B12

"Vitamin B12 helps your body metabolise amino acids (the building blocks of hair) and keeps your red blood cells healthy, allowing them to supply adequate oxygen to your tissues, including your hair follicles," explains Kingsley.

As B12 is primarily obtained from animal sources, vegetarians and vegans need to be especially mindful of their intake. Low levels of B12 can lead to hair thinning, as well as fatigue, weakness, and neurological symptoms.

Biotin

Biotin, often dubbed the 'hair vitamin', plays a role in metabolising proteins, fats, and carbohydrates, converting food into energy. "Hair cells are the second fastest-dividing cells the body makes, so available energy is important," says Kingsley.

However, Kingsley stresses that biotin deficiency is rare. "Taking a pure biotin supplement isn’t going to stop hair loss unless it’s directly related to a biotin deficiency," she explains. A well-rounded approach to supplementation is usually more effective.

Zinc

A lack of vitamin D is another common factor in hair thinning. Known as the 'sunshine vitamin', it’s crucial for follicle health. Low levels can disrupt the hair’s natural growth cycle, leading to increased shedding. Spending time outdoors and incorporating fortified foods can help maintain healthy levels.

Related article: The 10 Best Superfoods To Boost And Strengthen Your Immune System

Do vitamin supplements help with hair loss?

While supplements can be part of the solution, Kingsley and Gkini both stress the importance of understanding the underlying cause of hair loss. "Taking a well-formulated base supplement is a good place to start, and you can add in extra things if necessary," says Kingsley.

However, she adds a caveat: "People should be wary of taking too much and ideally have blood tests to check their levels after three months. Additionally, it’s important to identify the root cause. If your hair loss isn’t due to a nutritional deficiency, then taking supplements won’t be effective, no matter how many you take."

The takeaway? While supplements can support hair health, a balanced diet filled with protein, vegetables, and whole grains is just as crucial. Not only does it provide essential vitamins and minerals, but it also helps your body absorb them more efficiently. For persistent or worrying hair loss, always seek advice from a healthcare professional to find the right solution for you.

This article was first seen on ELLE UK.