If you have lines on your nails, it means you have ca…See more

brittle nails. One study found a 25% increase in nail thickness after 6-9 months of supplementation.

How it works: Biotin is a cofactor for enzymes involved in keratin production. Keratin is the structural protein that makes up your nails, hair, and skin. Without sufficient biotin, keratin structure is compromised.

Food sources:

Eggs (especially the yolk)

Salmon and sardines

Nuts

and seeds (almonds, walnuts, sunflower seeds)

Sweet potatoes

Mushrooms

Cauliflower

Supplement note: Biotin supplements are widely available and generally safe (it’s water-soluble; excess is excreted). However, high-dose biotin can interfere with certain lab tests (thyroid, cardiac troponin). If you take biotin