When it comes to growing healthy hair and nails, you’ve probably already seen all the ads for supplements containing certain nutrients that can help, such as vitamins A, E and D, along with iron, fats, carbs and protein. You’ve probably also heard about biotin, a B vitamin, that can help.

But there’s another key, and you’ll probably like it more — two words: eating enough.

It plays a bigger role than you may realise, too. “Our hair and nails are among the first signs of poor nutrition and/or nutritional deficiencies because hair and nail cells have a rapid turnover rate,” said Shelley Balls, a registered dietitian and nutritionist (RDN) for Flawless Bloom.

How is that the case, though, and what does it look like in practice? We talked to registered dietitians and dermatologists to find out.

How A Healthy Diet Aids Nail And Hair Growth

In the same way that your body needs calories and nutrients for cognition, organ function and moving around, it also needs calories to help your nails and hair grow. Not enough food means not much (or any) growth.

“If you’re under-eating, your body doesn’t have enough energy to use for all of its processes, including hair and nail cell growth and regrowth,” said RD Caroline Young, owner of Whole Self Nutrition. “Under-eating can also lead to nutritional deficiencies, which can negatively impact hair and nail growth.”

After all, other body parts obviously have priority when your body is running on limited calories.

“The body prioritises its vital organs, sending nutrients there first to ensure you can keep functioning,” said Dr. Anna Chacon, a board-certified dermatologist. “Improper nutrition can cause [hair and nail] shedding, brittleness and eventually loss if not properly cared for.”

From a related perspective, it’s necessary to consider what nails and hair are made of at a compound level. “Your hair and nails are both made of

© HuffPost