Most dermatologists agree that healthy hair (and skin) starts from within. If you eat a healthy diet with plenty of fruits, vegetables and healthy fats, your hair should be strong and lustrous. But let’s face it, busy lifestyles make it hard to meet the proper nutritional requirements. Plus, unhealthy habits, such as smoking or crash diets, stress, trauma from hairstyles, harsh products and treatments, environmental pollutants, illnesses and certain medications might make taking a multivitamin necessary.

While many health care professionals, especially nutrition experts, suggest we get our nutrients from a good diet, Taz Bhatia, MD, a certified nutritionist and board-certified physician, believes supplements can be important to overall health. “I am so tired of doctors saying that diet is enough,” says Bhatia. “Our food has poorer micronutrient quality than 50 years ago, and we as individuals have very specific nutritional needs. For example, I am always low in B and iron.” 

“I think beauty is tied to wellness, and taking supplements that are targeted to your health is one of the biggest beauty secrets,” she adds. “For example, many women are deficient in fatty acids, and taking a good fat supplement, like an omega-3, can improve skin and hair.”

But how do you know when to turn to supplements to improve the health of your mane? “When hair is brittle and breaks easily, it is usually a nutritional deficiency,” Bhatia says.

Angela Mastaloudis, PhD, a senior scientist at Pharmanex and Nu Skin Enterprises, a company engaged in antiaging research, agrees. “A number of nutritional deficiencies are associated with impairments in hair health,” she explains. For example, not getting enough vitamin A, iron or zinc is linked to dry, unhealthy scalp conditions.

One problem with vitamins is that they are classified as dietary supplements, which means they don’t have to get FDA approval before they’re marketed to consumers. As a result, there isn’t sufficient scientific data to confirm that hair supplements work.

Experts caution that people should be particularly skeptical about vitamins promising long, luscious tresses. Hair growth is determined by genetics, age, hormones and gender; vitamins cannot change the rate at which your hair grows. Additionally, it could take two to three months to see any benefits vitamins might impart to the hair. What’s more, if you have a nutritional deficiency, your vital organs will hijack the nutrients in supplements for themselves before allowing hair follicles to get their share.

Another point to remember is that without knowing the exact amount of nutrients a supplement contains, we can accidentally take too much of a good thing. “I think knowing what you are taking and not taking too much may be something to look out for,” Bhatia says. “For example, the fat-soluble vitamins, such as A, D, E and K, can be toxic at higher doses if stores of these nutrients in your body are already high.”

In addition, a diet rich in lean proteins, healthy fats and colorful fruits and vegetables is important for optimal scalp and hair health. “A variety of essential nutrients are involved in hair and scalp health, including, but not limited to, protein, essential fatty acids (including omega-3 fatty acids), vitamin A, B vitamins (biotin, folate, niacin, riboflavin, thiamin, pantothenic acid, vitamin B-6, vitamin B-12), vitamin C (ascorbic acid), vitamin E, chromium, copper, iron, selenium, silicon and zinc,” Mastaloudis says.

To ensure you’re taking the right nutrients, get tested for deficiencies and ask your health care professional to recommend brands of good vitamins. And check the labels on these products to see whether they’re certified. Are the bottles marked with seals, such as a GMP (good manufacturing practices) or NSF (a public health and safety organization) stamp?

Do your due diligence, Bhatia advises, “Look at the ingredients on the bottle, make sure each one is clearly listed and that its amount is given as well.”