Although they may not seem useful outside of making a beauty statement, fingernails are an important indicator of health. Fingernails require vitamins and nutrients just like every organ in the body. Certain nail problems can signal an illness or a need for vitamins or minerals. A well-balanced diet with essential vitamins can help promote long and strong fingernails.
Vitamin A is a fat-soluble vitamin that can help prevent fingernails from becoming brittle and cracking. Good sources of vitamin A include carrots, sweet potatoes and spinach. According to the Institute of Medicine's Food and Nutrition Board, the recommended amount of vitamin for adults is 700 mcg for females and 900 mcg for males. More than 3,000 mcg of vitamin A per day can be dangerous, as stated in Harvard Health Publications.
According to the Mayo Clinic website, biotin may help increase nail thickness. Thicker nails are tougher and lead to less breakage, allowing them to grow longer. Biotin is a B vitamin found in foods such as eggs, fish and soybeans. It can also be found in supplement form. The daily amount recommended by the Institute of Medicine's Food and Nutrition Board is 30 mcg.
Vitamin C helps the body make collagen, a structural element that helps form the nose, ears, hair and nails. Oranges, tomatoes, peppers and strawberries are rich in vitamin C. The Institute of Medicine's Food and Nutrition Board recommends 90 mg of vitamin C per day for men and 75 mg per day for women.
According to Harvard Health Publications, vitamin D helps regulate calcium and phosphorus, two minerals that are important to bone, hair and fingernail health. Though vitamin D is found in fortified milk and cereals, the main source of vitamin D is sunlight. People who live in northern climates might not get enough sunshine and may require supplements.