Your nails are an outward show of your inner health, and they may display malnutrition or signs of disease, such as heart disease or diabetes. Nails are important as they protect and support the tissues in your fingers. Dry nails can indicate a few different problems and may suggest a diet lacking in certain nutrients.
The nail is made up of laminated layers of protein called keratin, according to the Mayo Clinic. They grow from the area at the base of the nail. From under the cuticles, new cells grow and old cells become hard and compact, forming your visible nail. A healthy nail is smooth, uniform in color and consistent and does not have ridges, grooves, spots or discoloration. Vertical ridges are harmless and may develop with age.
Dry, brittle nails may just be a sign of aging, according to MedlinePlus, but could also indicate underlying health conditions. Thyroid diseases such as hyperthyroidism and hypothyroidism can cause brittle nails or nail splitting, a condition called onycholysis. Dry, brittle nails that split vertically may be from heredity or household cleaning solutions. Nail psoriasis is raw, scaly skin and causes the nail plate to dry and crumble. Malnutrition or vitamin deficiency can lead to unhealthy nails from a lack of moisture.
The state of your nutrition affects the fingernails and tissues, such as nails grow at a rapid rate, making them easy to measure for growth rate. A change in the nails could provide information on nutritional deficiency states, according to "The Journal of Nutrition." Changes in the nails thought to be associated with nutrition include transverse, longitudinal ridging, brittleness and the "spoon nails." Nutrients associated with a change in the look of nails are vitamins, iron, calcium, zinc, fluorine, protein and unsaturated fats. Though nails are comprised of mostly keratin, a type of protein, the way the tissue is formed suggests that nails involve cholesterol, various metals and at least 11 other nutrients.
Dry, brittle nails could indicate a deficiency in calcium, vitamin A, protein and iron, according to the Nestle Family website. Biotin, most commonly associated with nail health, is often used to treat brittle nails, according to the Skin and Aging website. Minerals such as zinc, selenium and silicon are also good for nails. Food sources that contain biotin include egg yolks, yeast, nuts and soybeans. Milk and dairy products are great sources for protein, calcium and zinc. Lean meats, fish and poultry provide protein, iron and zinc, as do legumes. Vitamin A-rich foods include green, leafy vegetables and yellow or orange vegetables.
Nails can tell a lot about a person, so contact your doctor first to determine the reason for your dry nails and before beginning any vitamin supplements. Overall good nutrition will help give you healthy nails. Drink plenty of water to keep them hydrated as well.