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If you're noticing more hair in your brush than usual, it might not just be stress or styling - it could be a sign your body is missing essential nutrients. So, which vitamin deficiency causes hair loss? The truth is, more than one vitamin can impact hair health. In fact, several deficiencies are linked to thinning, shedding, or stunted growth.
In this guide, we’re breaking down the top 10 vitamin deficiencies that cause hair loss in women, why they matter, and how to support healthy hair growth from within - and from the outside, too.
1. Biotin (Vitamin B7)
Biotin is often called the “hair growth vitamin” for a reason. It plays a major role in the production of keratin - the protein your hair is made of. Low biotin levels can lead to brittle strands, increased breakage and noticeable thinning.
How to support it: Look for supplements like Pump Mermaid Hair Growth Vitamins, which contain biotin as a key active ingredient.
2. Iron
Iron deficiency (especially common in women of reproductive age) is one of the most frequent causes of hair loss. Iron helps red blood cells carry oxygen to hair follicles — and when stores are low, hair growth can slow or stop altogether.
Tip: Ferritin, a protein that stores iron, is closely linked to hair health. Even if your iron levels seem normal, low ferritin can still trigger shedding.
3. Vitamin D
Often dubbed the “sunshine vitamin,” vitamin D stimulates hair follicles and plays a key role in new hair growth. A deficiency has been linked to alopecia areata and general hair thinning.
Getting enough: Spend time outdoors safely or consider supplementation, especially during winter or if you're mostly indoors.
4. Zinc
Zinc contributes to hair tissue growth and repair, and helps keep the oil glands around follicles working properly. A lack of zinc can lead to both hair shedding and scalp issues like dandruff or irritation.
5. Vitamin A
While vitamin A is crucial for healthy hair growth, both too little and too much can cause problems. A deficiency may result in dry hair and a flaky scalp, while excess amounts can actually lead to hair loss.
Balance is key — always stick to recommended daily intake guidelines.
6. Vitamin C
This antioxidant powerhouse supports iron absorption (see point #2) and helps the body produce collagen, which strengthens hair structure. A deficiency in vitamin C can lead to weak, brittle strands and slower growth.
Bonus: It also protects hair follicles from oxidative stress. Our Mermaid Lengths Spray Contains Vitamin C.
7. Adaptogens like Ashwagandha
Chronic stress is one of the most overlooked causes of hair loss in women. Adaptogens like ashwagandha root extract help support your body’s natural stress response, which in turn can improve hormonal balance and reduce stress-related hair shedding.
Natural support: Ashwagandha is one of the key active ingredients in Pump Mermaid Hair Growth Vitamins, chosen for its calming and restorative benefits.
8. Vitamin B12
This energy-boosting vitamin helps create red blood cells that deliver oxygen to your scalp and follicles. A deficiency may cause hair thinning, fatigue, and pale skin.
Who’s at risk? Vegans and vegetarians often need to supplement, as B12 is mostly found in animal products.
9. Folate (Vitamin B9)
Folate plays a role in the synthesis of DNA and red blood cells, both vital for growing healthy hair. Low levels may interfere with follicle function and growth cycles.
10. Essential Fatty Acids (Omega-3s)
While technically not a vitamin, omega-3 fatty acids are crucial for scalp health. They nourish hair, support hydration and help reduce inflammation — all essential for maintaining strong, healthy strands.
So, do vitamin deficiencies cause hair loss?
Absolutely. While genetics, hormones and styling habits all play a role in hair health, vitamin and mineral deficiencies are often overlooked triggers. The good news? They’re usually easy to correct with the right supplementation and lifestyle changes.
What You Can Do About It
While fixing your diet and addressing deficiencies is a great start, it's only part of the solution. Coupling vitamin intake with a solid haircare routine is essential.
At Pump Haircare, we believe in a 360° approach to women’s hair health. In addition to the Pump Mermaid Hair Growth Vitamins (which also feature Biota Orientalis extract and ashwagandha root extract to support hair growth and reduce stress-related shedding), we recommend using a salon-quality shampoo, conditioner, hair mask and hair growth serum.
Together, these steps help nourish hair at the root, strengthen strands mid-length, and protect the ends.
Understanding which vitamin deficiency causes hair loss is a powerful first step toward restoring your hair’s thickness, shine, and strength. If you're struggling with shedding or stunted growth, it might be time to assess your nutrition - and your haircare routine.
When you combine internal nourishment with targeted haircare products, your hair has the best chance to thrive.
