- Iron Deficiency: “Iron is crucial for red blood cell production, which delivers oxygen to hair follicles,” says Kim. A deficiency can lead to thinning hair and even hair loss. Iron deficiency is particularly common in women due to menstrual blood loss, making it one of the most prevalent nutritional deficiencies associated with hair loss. Ensuring adequate iron levels through diet or supplementation can help support healthy hair growth; good sources of iron include red meat and leafy green vegetables like spinach.
- Vitamin D Deficiency: Vitamin D plays a role in the creation of new hair follicles, and a deficiency can result in slow hair growth or hair loss, explains Kim. He says, “It’s best to get natural sunlight to create your own vitamin D—go for a brisk walk either early in the morning or later in the day and get 15 to 20 minutes of sun exposure.” He also recommends oral vitamin D supplementation, adding that it’s important to include a magnesium supplement to help convert vitamin D into its active form.
- Zinc Deficiency: Kim explains that zinc is essential for tissue growth and repair, including hair. “Low levels of zinc can lead to hair thinning or loss.”
- Biotin (Vitamin B7) Deficiency: Biotin supports the production of keratin, the protein that makes up hair. “A deficiency can cause brittle hair and hair loss,” says Kim.
- Protein Deficiency: Hair is primarily made of protein. “Inadequate protein intake can cause hair to become weak and fall out,” says Kim.
- Iodine Deficiency: “Iodine deficiency can cause hair loss, as iodine is a crucial mineral needed for the production of thyroid hormones, which regulate many bodily functions, including hair growth,” explains Kim. When iodine levels are low, the thyroid gland can’t produce enough hormones, leading to a condition called hypothyroidism. Ensuring adequate iodine intake through diet, or supplementation if necessary, is important for maintaining healthy thyroid function and preventing hair loss related to iodine deficiency.
Are there any side effects to be aware of?
“There are always potential side effects,” says Gordon, emphasizing the importance of sourcing botanicals from reputable sources due to limited studies. While many botanicals target dihydrotestosterone, which may lead to low testosterone side effects, such occurrences are generally rare. Excessive biotin intake can result in acne and should be discontinued before certain blood tests to avoid lab interference. Iron supplements may cause constipation, and collagen may induce diarrhea or gastrointestinal upset in some individuals.
How long do hair growth vitamins take to work?
“Hair growth is a slow process, with hair typically growing about half an inch per month,” explains Kim. Hair growth vitamins, which often include biotin, vitamin D, zinc, and other nutrients, are designed to support the body’s natural hair growth cycle. However, results may vary depending on factors such as genetics, gut absorption issues, hormonal dysfunction (e.g., PCOS), poor thyroid function, diet, and lifestyle factors like stress. Despite these challenges, he notes that with the right approach, some individuals may start noticing improvements in hair texture and reduced shedding within a few weeks, while significant growth and thicker hair strands may take three to six months. As with any other kind of supplement intake, consistency is key—“stopping supplementation or failing to address root issues like hormone imbalances and gut health can quickly undo the progress made in achieving healthy hair growth,” says Kim.
How should you choose the hair growth vitamin for you?
You should choose hair growth vitamins based on your specific needs. According to Song, the first step is to identify potential causes of hair thinning, such as nutrient deficiencies, stress, or hormonal imbalances. “Look for well-rounded ingredients, such as a multivitamin that includes vitamin D, Zinc, and iron,” she advises. Always consult with your health expert on additional guidance on addressing any deficiencies, especially if you are not sure of the cause of your hair loss. When shopping, always opt for a reputable brand with well-established clinical data to support its efficacy.
When should you see a doctor about hair loss/thinning?
In general, everyone experiences some degree of hair loss over time. “It is normal to shed up to 100 hair strands a day,” says Song. However, she advises seeking professional consultation if hair loss is sudden or excessive, such as clumps of hair falling out, bald spots, or significant thinning concentrated in specific areas. Scalp symptoms like itching, pain, or flaking may also cause hair loss and require medical treatment. Additionally, it’s important to see a doctor if hair thinning is accompanied by systemic symptoms like fatigue or weakness, as these may warrant blood work to identify underlying conditions. Song also notes that if you’ve tried your own treatment regimen and haven’t seen improvement after 3 to 6 months, it’s time to seek a dermatologic evaluation.
Meet The Experts
- Dr. Hardik Doshi is a double board-certified plastic surgeon and the lead surgeon for hair restoration at Ample.
- Dr. Jennifer Gordon is a board-certified dermatologist at Westlake Dermatology.
- Alisa Vitti, HHC, AADP, is a functional nutrition and women’s hormone expert, the founder of modern hormone health care company FLO Living.
- Dr. John Kim is a functional medicine pharmacist and the founder of Dr. Kim Wellness in New Jersey.
- Dr. Pooja Rambhia is a board-certified dermatologist with specialized fellowship training in cosmetic dermatology and laser surgery at Union Derm in New York City and Greenwich, CT.
- Dr. Teresa Song is a New York-based board-certified dermatologist at Marmur Medical.
