Which Vitamin Deficiencies Are Linked to Hair Loss?

Which Vitamin Deficiencies Are Linked to Hair Loss?

• July 14, 2025
• Dr Paul Spano

Last updated on July 14, 2025

Hair loss can happen for many reasons — from genetics and hormonal changes to stress and medical conditions. But one often-overlooked factor is nutrition. Your hair follicles rely on a steady supply of vitamins and minerals to function properly, and when your diet falls short, your hair may suffer. Here, our hair growth clinic in Melbourne explores which vitamin deficiencies are most commonly linked to hair loss and what you can do to support healthy hair growth.

The Role of Nutrition in Hair Health

Hair is one of the fastest-growing tissues in the body, but it’s not essential to survival. This means your body will prioritise other systems when nutrients are scarce. As a result, hair health can be one of the first areas affected by poor nutrition.

When the body isn’t getting the vitamins and minerals it needs, it may cause the hair growth cycle to shift — leading to slower growth, weaker strands, or increased shedding.

Key Vitamin Deficiencies Linked to Hair Loss

Let’s take a closer look at the most common vitamin and nutrient deficiencies associated with hair loss in both men and women.

1. Iron Deficiency

Iron deficiency is one of the most well-known nutritional causes of hair loss, particularly in women. Iron is essential for producing haemoglobin, a protein in red blood cells that carries oxygen to the body’s tissues, including hair follicles.

When iron levels are low, follicles may receive less oxygen, which can impact growth and lead to excessive shedding — especially in the form of telogen effluvium.

Signs of deficiency:

• Fatigue
• Pale skin
• Brittle nails
• Cold hands and feet

Foods rich in iron:

• Red meat
• Lentils
• Spinach
• Fortified cereals

2. Vitamin D Deficiency

Vitamin D plays a role in the creation of new hair follicles and helps regulate the growth cycle. A lack of this vitamin has been linked to alopecia areata, an autoimmune form of hair loss, as well as general thinning.

Since vitamin D is produced when the skin is exposed to sunlight, people who spend a lot of time indoors or live in low-sunlight areas are at higher risk of deficiency.

Signs of deficiency:

• Muscle weakness
• Low mood
• Frequent infections
• Bone pain

Sources of vitamin D:

• Sunlight
• Fatty fish (like salmon)
• Egg yolks
• Fortified milk and juices

3. Biotin (Vitamin B7) Deficiency

Biotin is part of the B-vitamin family and helps convert food into energy. It also supports keratin production, the protein that makes up your hair. Although a true biotin deficiency is rare, low levels can affect hair strength and growth.

It’s sometimes used as a supplement to improve hair condition, although its effectiveness is most noticeable in people who are deficient.

Signs of deficiency:

• Thinning hair
• Scaly scalp
• Brittle nails
• Fatigue or muscle pain

Biotin-rich foods:

• Eggs
• Almonds
• Sweet potatoes
• Seeds

4. Vitamin B12 Deficiency

Vitamin B12 helps produce red blood cells and supports nerve function. A deficiency can reduce oxygen delivery to the scalp and cause hair thinning or shedding. This is more common in vegans and vegetarians, as B12 is found mostly in animal products.

Signs of deficiency:

• Fatigue
• Brain fog
• Pale skin
• Tingling in hands or feet

Food sources:

• Meat
• Fish
• Dairy products
• Fortified plant milks

5. Zinc Deficiency

Zinc is a trace mineral essential for cell growth, tissue repair, and oil production in the scalp. A lack of zinc has been associated with both hair loss and poor wound healing. Like biotin, zinc is often found in hair growth supplements.

Signs of deficiency:

• Hair shedding
• Dry, flaky scalp
• Slow wound healing
• Weakened immune system

Zinc-rich foods:

• Oysters
• Beef
• Pumpkin seeds
• Chickpeas

6. Vitamin A Deficiency (and Excess)

Vitamin A supports cell growth, including hair, and helps produce sebum, the oily substance that keeps the scalp moisturised. However, both too little and too much vitamin A can lead to hair loss.

Excessive vitamin A (often from supplements) can trigger shedding, while a deficiency may lead to dry hair and scalp.

Signs of deficiency:

• Dry hair
• Vision problems
• Dry skin

Foods with vitamin A:

• Sweet potatoes
• Carrots
• Dark leafy greens
• Liver

How to Know If You’re Deficient

If you’re experiencing unusual hair loss, it’s important not to self-diagnose. Hair shedding can be triggered by many factors, and overdosing on supplements can be harmful. The best way to determine if a vitamin deficiency is contributing to hair loss is to speak with a medical professional and request a blood test.

They’ll assess your overall health, lifestyle, and diet, and help pinpoint any imbalances that could be affecting your hair.

Can Supplements Help with Hair Loss?

If you have a confirmed deficiency, targeted supplementation can support recovery and hair regrowth. However, for people with normal nutrient levels, adding high-dose vitamins may not provide additional benefits — and in some cases, it can do more harm than good.

Supporting your hair through a balanced diet, gentle hair care, and professional treatments is usually more effective than supplements alone.

Supporting Hair Regrowth With Professional Hair Growth Treatments

If you’ve corrected nutritional deficiencies but hair loss continues, there may be another cause — such as genetic factors, hormonal changes, or chronic conditions. At Hair Transplants Melbourne, we specialise in identifying the cause of hair loss and creating a treatment plan tailored to your needs.

Our clinic offers a wide range of medically backed hair growth solutions for women and hair loss treatments for men, including FUE and FUT hair transplants, Liquid Hair Therapy, scalp micropigmentation, growth factor treatment, Regenera stem cell therapy, and more.

Book a consultation or a free 15-minute phone chat with our experienced Melbourne-based team to explore how we can help you restore and maintain healthy, natural-looking hair.

FAQs

Does lack of vitamin D cause hair loss?

Yes, a lack of vitamin D can cause hair loss. It helps regulate the hair growth cycle and plays a role in creating new follicles. Deficiency has been associated with thinning hair and conditions like alopecia areata. If you suspect low vitamin D levels, a blood test can confirm it. Hair Transplants Melbourne offers supportive treatments for hair loss caused by nutritional and hormonal factors. Book a free 15-minute call with our team.

What vitamin is good for hair loss recovery?

Several vitamins are beneficial for hair loss, including vitamin D, biotin, B12, and iron. These nutrients help support hair follicle health, oxygen delivery, and keratin production. If you’re wondering what vitamin is good for hair loss in your case, professional testing is the best first step. Our team at Hair Transplants Melbourne can help identify the cause and create a tailored treatment plan. Book your hair loss consultation or free phone call to start the process.

Does vitamin D help with hair loss regrowth?

Vitamin D may help with hair loss regrowth, especially if your levels are low. It contributes to follicle health and regulates the hair growth cycle. While supplements can help correct deficiencies, long-term hair loss may need professional care. At Hair Transplants Melbourne, we offer expert assessments and advanced therapies that work alongside nutritional support. Book a 15-minute phone consultation to explore your options.

Can too much vitamin A cause hair loss?

Yes, too much vitamin A can actually cause hair loss. Over-supplementing can push hair follicles into the shedding phase. Conversely, too little can result in a dry scalp and brittle strands. It’s all about balance. If you’re experiencing unexplained shedding, our doctors at Hair Transplants Melbourne can help identify the issue and recommend safe, effective treatments. Book a consult or free phone chat to discuss your concerns.

How do I know if a vitamin deficiency is causing my hair loss?

Symptoms like fatigue, pale skin, brittle nails, and thinning hair may point to a vitamin deficiency. A blood test is the best way to confirm. If you’re asking which vitamin deficiency causes hair loss in your case, we can help. Hair Transplants Melbourne offers in-clinic assessments and expert advice, as well as hair growth treatments for women and hair loss solutions for men. Book a consultation or a free 15-minute phone call to get personalised guidance.

What’s the best way to treat hair loss caused by vitamin deficiencies?

The best approach starts with identifying which deficiency is present. This is followed by correcting it through diet, supplements (if needed), and gentle hair care. If you’re still losing hair after addressing nutrition, professional treatments may help. Hair Transplants Melbourne offers growth factor treatment, gold standard Liquid Hair Therapy, stem cell treatments and more, many of which boost scalp and hair health while stimulating hair growth. Book a consultation or free 15-minute phone call to find the right solution for you.