Calcium is essential for bones and overall health, but when it comes to nail strength, other nutrients play a bigger role. Here’s what to focus on instead.

Q: My nails are always brittle and breaking. I’ve heard that calcium strengthens nails. Will taking supplements help?

A: Like hair, nails are made mainly of the hardened protein keratin, which means that the foods that create beautiful hair also help nails stay strong. For example, protein and biotin are necessary for nail growth and strength, zinc keeps nails from weakening, and iron keeps nails from distorting into spoon shapes. Just as high doses of selenium can cause may result in hair loss, too much selenium can also lead to nail loss (yikes!). Here’s a bit more info on exactly how to help your nails grow super strong, as evidenced by the research.

Nutrients that Actually Support Nail Health

Although many people believe that calcium supplements help build strong nails, research doesn’t support the notion. Researchers from New Zealand examined the effects of calcium on nail health. Nearly 700 postmenopausal women took 1,000 milligrams of calcium every day for a year. At the end of the study, the women reported no change in nail strength. So, although I heartily recommend calcium for so many different health issues, nail health isn’t among them.

Here are the nutrients I recommend looking at if optimal nail health is your goal:

  • Protein: Nails are made mostly of keratin, a hardened protein, so it makes sense that getting enough protein is key for nail strength and growth. Research shows that low-protein diets are often linked with weak, brittle nails, so make sure to include quality sources like eggs, fish, beans, and lean meats.
  • Biotin: Biotin (a B vitamin) plays a role in supporting keratin infrastructure, which is why it’s often used for brittle nails and nail breakage. Research suggests biotin supplementation may improve nail thickness and reduce splitting in people with fragile nails—so it can be a smart add-on if your nails constantly peel, chip, or snap. You can also boost your intake with biotin-rich foods like eggs, salmon, sweet potatoes, avocado, nuts and seeds (like almonds and sunflower seeds), and beans/lentils.
  • Zinc: This mineral helps your body build the proteins that form nail tissue, keeping nails from thinning or developing white spots. Studies suggest zinc deficiency is a common cause of slow nail growth and fragility, so enjoy zinc-rich foods like pumpkin seeds, chickpeas, and yogurt.
  • Iron: Without enough iron, nails can develop “spooning” (a concave shape) and become brittle. Research connects iron-deficiency anemia with nail changes, so fueling up with iron-rich foods like spinach, lentils, and lean beef can make a big difference.
  • Selenium: In small amounts, selenium supports nail growth by helping the body process proteins. But here’s the kicker: too much selenium can actually cause nail loss, according to studies. Stick with balanced food sources like Brazil nuts, seafood, and whole grains (and remember: just 1–2 Brazil nuts a day is plenty!).

The Best Foods for Strong Nails

  • Eggs
  • Salmon and other fatty fish
  • Chicken and turkey
  • Beans and lentils
  • Spinach and kale
  • Pumpkin seeds
  • Chickpeas
  • Yogurt
  • Lean beef
  • Fortified whole-grain cereals
  • Brazil nuts (just 1–2 per day)
  • Whole grains (oats, brown rice, quinoa)

Your nails are a good indicator of overall health and diet quality. For strong, beautiful nails, focus on a balanced diet filled with colorful produce, whole grains, and lean proteins. Want inspiration? Check out my recipe library for delicious, nail-health-boosting meals and snacks that make it easy to eat your way to healthier nails