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  • Dr. Brooke Grant Jeffy (Dermatologist)

Uncovering the Role of Nutrition for Healthy Hair


Hair problems are one of the most distressing issues to my patients, male or female. A healthy full head of hair evokes youth and vitality. Hair loss or other hair related issues can be incredibly distressing and rob us of our confidence. I often say to patients that problems with the hair are so challenging and complicated because so many factors influence our hair - genetics, age, stress, nutrition, hormones, medications and hair care practices. Today I am going to focus on the role of nutrition for healthy hair since there is so much marketed to us in this realm.

Calories. Our hair follicles require adequate energy to function. Dieting and rapid weight loss often lead to hair loss. If weight loss is a goal, make sustainable long term changes such as focusing on a plant based diet instead of excessive calorie restriction. Diets less than 1000 calories per day can lead to hair loss.

Vitamins. Vitamin D deficiency can cause hair loss and vitamin C deficiency may lead to reduced hair strength and growth. Adults practicing sun protection should ingest approximately 800 international units of vitamin D daily. Vitamin C ingestion for women should be at least 75 mg per day and 90 mg for men but will generally be met with a diet rich in vegetables and fruits. Biotin (vitamin b7) is often touted for hair loss. Unfortunately there is no evidence that taking biotin improves hair growth unless you are deficient which is rare with a varied diet, with or without meat.

Minerals. Adequate iron is needed for hair growth. Zinc and copper are necessary for hair strength as well as growth. A healthy diet will generally meet our daily iron needs, 8 mg for men and 18 mg for women, even a vegetarian one. Zinc and copper deficiency are rare in otherwise healthy adults with a varied diet.

Probiotics. There are studies in mice showing increased hair growth in mice taking probiotics containing Lactobacillus reuteri but no human studies.

Herbs. There are small human studies showing improved hair growth with supplements containing saw palmetto, green tea, pumpkin seed and rosemary.

Collagen. There have been no studies on collagen supplementation and hair growth however in studies done on skin effects, the perception of hair improvement was noted in terms of strength and growth.

The bottom line is that a varied diet with adequate calories and a vitamin D supplement should cover your hair's nutritional needs. You need that vitamin D because you are practicing strict sun protection, right? The marketing of ingredients in hair supplements is based on studies showing improvement when there is an actual deficiency which of course makes sense. I think there is reasonable evidence to consider a collagen supplement and I think we should all be ingesting green tea for its powerful antioxidant benefits on our entire body. I do recommend saw palmetto in certain types of hair loss but not for general hair maintenance.


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