Keratin is a type of structural protein found in your hair, skin, and nails (1).

It’s especially important for maintaining the structure of your skin, supporting wound healing, and keeping your hair and nails healthy and strong (1).

Keratin supplements are often said to help prevent hair loss, increase nail growth, and improve skin texture. Yet, plenty of healthy foods may naturally support your body’s synthesis of keratin.

Here are 10 foods that promote keratin production.

Eating eggs is a stellar way to boost keratin production naturally.

In fact, they’re a great source of biotin, an essential nutrient involved in keratin synthesis. A single cooked egg provides 10 mcg of this nutrient, or 33% of the Daily Value (DV) (2, 3, 4).

What’s more, eggs’ protein promotes keratin production, with 6 grams of protein packed into one large, 50-gram egg (2).

Other healthy nutrients in this ubiquitous food include selenium, riboflavin, and vitamins A and B12 (2).

Onions are not only great for flavoring your favorite dishes but also ramping up keratin production.

This allium vegetable is especially high in N-acetylcysteine, a plant antioxidant that your body converts into an amino acid called L-cysteine — a component of keratin (5, 6).

Onions also provide folate, an essential micronutrient necessary for maintaining healthy hair follicles (7).

Salmon is brimming with protein, packing nearly 17 grams per 3-ounce (85-gram) serving (8).

It’s also an excellent source of biotin, another key nutrient that supports keratin production. Just 3 ounces (85 grams) of canned salmon contain 5 mcg, or 17% of the DV (4).

This fish is also high in omega-3 fatty acids, a type of heart-healthy fat that has been shown to help improve hair growth, enhance hair density, and protect against hair loss when used in supplement form (9, 10).

In addition to being one of the most vibrant vegetables, sweet potatoes are highly nutritious and great for promoting keratin production.

They’re particularly high in provitamin A carotenoids. Provitamin A carotenoids like beta carotene are converted into vitamin A in the body.

A medium sweet potato (about 150 grams) provides 1,150 mcg — over 100% of the DV — of provitamin A. Vitamin A promotes keratin synthesis and is essential for skin and hair health (7, 11, 12, 13).

Each serving of this orange root veggie contains a hearty dose of potassium, manganese, and vitamins B6 and C as well (11).

Sunflower seeds are savory, satisfying, and flavorful.

They’re also a great source of both biotin and protein to support keratin production. Just 1/4 cup (35 grams) offers 7 grams of protein and 2.6 mcg of biotin — 9% of the DV (4, 14, 15).

What’s more, these seeds are rich in a variety of other micronutrients, including vitamin E, copper, selenium, and pantothenic acid (14).

Native to South Asia, mangoes are a tasty way to squeeze extra nutrients into your diet while supporting keratin synthesis.

In particular, this tropical stone fruit is packed with provitamin A, with 89 mcg — nearly 10% of the DV — in each cup (165 grams) (16).

Mangoes are also high in several other key nutrients for skin and hair health, such as vitamin C and folate (16).

Much like onions, garlic boasts plenty of N-acetylcysteine, which your body turns into L-cysteine — an amino acid found in keratin (5, 6).

Although more research in humans is needed, some studies suggest that garlic may aid skin health. For instance, one test-tube study found that garlic extract protected keratinocyte cells, which are responsible for keratin production, from ultraviolet damage (17, 18).

Test-tube and animal studies further suggest that this popular allium vegetable may promote wound healing, fight microbial infections, and slow signs of aging (17).

Garlic also boasts many beneficial micronutrients, including manganese, vitamin B6, and vitamin C (19).

Kale is known for its impressive nutrient profile.

This leafy green vegetable is a good source of provitamin A to support keratin synthesis, boasting 50 mcg in just 1 raw cup (21 grams), which is about 6% of the DV (20).

It’s also a great source of vitamin C, a water-soluble nutrient that doubles as an antioxidant. This vitamin likewise helps stimulate the production of collagen, a type of protein that maintains the strength, structure, and elasticity of your skin (20, 21, 22).

Beef liver is one of the most concentrated sources of biotin, making it a great choice if you’re looking to ramp up keratin production naturally.

In fact, just 3 ounces (85 grams) of cooked beef liver packs 31 mcg of biotin, exceeding your daily needs at 103% of the DV (4).

Plus, the same amount of beef liver provides an ample 24.5 grams of protein and 7,960 mcg of vitamin A — a whopping 884% of the DV (23).

Beef liver is also an excellent source of many other vitamins and minerals, such as vitamin B12, folate, riboflavin, and iron (23).

Carrots are a highly nutritious root vegetable closely related to celery, parsley, and parsnips.

In particular, carrots are high in provitamin A, with 1,070 mcg in 1 chopped cup (128 grams). That’s over 100% of the DV (24).

They’re also loaded with vitamin C, which promotes collagen synthesis to support hair, skin, and nail health. Plus, this vitamin aids wound healing, alleviates inflammation, and protects against skin damage (21, 22, 25).

In addition, carrots offer plenty of biotin, vitamin B6, potassium, and vitamin K1 (24, 26).

Keratin is a type of protein that boosts the health of your hair, skin, and nails (1).

Several specific nutrients are essential for keratin synthesis, including protein, biotin, and vitamin A.

Enjoying a balanced diet filled with foods rich in these nutrients can help promote keratin production in your body.

Not only do these foods enhance hair, skin, and nail health, but they’re also rich in many other beneficial nutrients.