A balanced diet provides all the nutrients needed for strong healthy fingernails. Shortages of important vitamins and minerals or a lack of protein could interfere with nail growth, but your fingernails also reflect your general state of health. Keratin, the same protein that forms the beaks of birds and the horns of animals, forms in layers at the root of the nail. Severe illness can interrupt keratin formation, and chronic disease can change fingernail shape, color and thickness.
Nutrition
If you eat a variety of healthy foods daily, you can avoid the shortages of iron, calcium and other important vitamins and minerals that affect the health of your fingernails and hair. Including fresh fruits and vegetables in your diet, along with whole grains and proteins from both plant and animal sources, provides a steady supply of critical nutrients. If you rely on only a few types of food or eat mainly processed foods and refined starches, you could lack important keratin-building blocks. Dry, brittle nails can result from dietary problems, but many types of chronic illness also affect the appearance of your nails. Improper nail care could also cause brittle, splitting nails.
Biotin
You need about 30 micrograms of biotin, or vitamin H, every day in order to process other nutrients you receive in food. Few people develop biotin deficiency, since many foods such as egg yolks, brewer's yeast, nuts, beans and sardines contain biotin. A healthy diet provides about 60 micrograms daily. Highly-processed foods contain less biotin than whole grains and other natural food products. If genetic problems cause your brittle nails, your doctor may prescribe biotin supplements to compensate. High doses of biotin could interfere with absorption of pantothenic acid, or vitamin B-5, so don't take biotin supplements without your doctor's advice.
Malnourishment
Even temporary malnutrition could weaken your nails and flaw their appearance for months. Healthy nails show parallel ridges running along the length of the nail. Deep horizontal flaws called Beau's lines form because of an interruption in nail nourishment. If you don't eat enough food or if your food lacks any single vitamin, nail growth slows. Returning to a proper diet restores growth to normal, leaving a horizontal groove in your nail.
Protein Deficiency
Protein deficiency could affect anyone severely restricting total food intake or food variety. Diets providing only a few plant-based foods contain incomplete proteins lacking some of the amino acids you need to build new tissue. If you're vegan, you need a variety of plant foods including whole grains, vegetables and legumes every day to ensure consumption of a full range of amino acids. Protein quantity also affects nail strength. If you weigh 150 pounds, you need about 60 grams of complete protein every day to maintain body tissues. Most American diets provide more, but starvation diets cause thinner fingernails along with many other serious health problems.
References
- Go Ask Alice!; Fingernails Fray and Chip All the Time; December 1999
- University of Maryland Medical Center; Vitamin H (Biotin); Steven D. Ehrlich; June 2009
- Linus Pauling Institute; Biotin; Jane Higdon; June 2004
- MayoClinic.com; Adult Health; November 2009
- University of Maryland Medical Center; Malnutrition; David Zieve; June 2011
- Harvard School of Public Health: Protein: Moving Closer to Center Stage
