The appearance of your fingernails reflects more than proper grooming -- it tells a lot about your diet, too. Poor nutrition can impact the tiny, raised lines known as striations or ridges that develop on the nail plate. While the vertical nail striations are fairly benign and common, the horizontal striations can signal a variety of underlying health conditions. Therefore, diet is an important consideration for having healthy and attractive fingernails.
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A single occurrence of horizontal striations may only signal that the body is fighting off an illness, while reoccurring lines may indicate a chronic disease that requires medical attention. Beau's lines are depressions across the fingernail associated with zinc deficiency. Koilonychia is an abnormal shape of the fingernail associated with iron deficiency. The nail has raised ridges and is thin and curved inward. Muehrcke’s lines form as paired white bands across the fingernail. These lines are linked to low levels of a protein called albumin in the body. Never self-diagnose; a doctor should confirm any abnormality and its degree of severity.
Lacking significant amounts of protein, iron, calcium or vitamins such as vitamin A and the B vitamins can lead to abnormal striations in nails. When the body does not get enough nutrients, malnutrition can occur. Reasons for malnutrition include not eating enough food or enough variety of food, starvation and lack of vitamins (even just one) in the diet. The impact of malnutrition can vary from being mild in nature with no symptoms to causing severe irreversible damage to the body. Since fingernails only grow at about 3 millimeters each month in adults, nail changes are not usually the first sign of disease including malnutrition. In addition to ridges, malnutrition may cause fingernails to flatten, scoop, split or become brittle.
To prevent or treat nail striations associated with malnutrition, it is important to maintain a balanced diet on a daily basis. Eat more fruits, vegetables and foods that contain omega-3 fatty acids like fish, nuts and seeds. Specifically, a lack of vitamin B-12, zinc and iron in the diet have been linked to fingernail problems. Therefore, eating foods containing these nutrients or taking supplements is ideal. In addition to food, drinking water each day ensures healthy body function.
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Vitamin B-12 is a water-soluble vitamin that is found naturally in animal products and added to other foods, like fortified breakfast cereals. The recommended dietary allowance for vitamin B-12 is 2.4 micrograms for adults. Eat fish, meat, poultry, eggs and milk, which naturally contain vitamin B-12, to help prevent fingernail ridges.
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Zinc is an essential mineral that plays a role in cellular metabolism. A daily intake of zinc is needed since it cannot be stored in the body. The RDA of zinc for adult men is 11 milligrams, and 8 milligrams for adult women. When pregnant, women need to increase their intake to 11 milligrams, and lactating women need 12 milligrams daily. Oysters are an excellent source of zinc, as they have 74 milligrams per 3-ounce serving, more than any other food. Other sources of zinc include red meat, poultry, seafood and dairy as well as beans, nuts and whole grains for vegetarian options.
Iron is an essential metal that supports the function of proteins and enzymes for good health. When selecting iron-rich foods, be mindful that the body absorbs heme iron better than nonheme iron. Heme iron is found in animal protein, while nonheme iron is found in plants. The RDA of iron for adult women is 18 milligrams; after the age of 50, women should reduce their intake to 8 milligrams. Adult men of all ages need 8 milligrams daily. Foods high in heme iron include chicken liver, oysters and beef liver. Foods high in nonheme iron include fortified cereals and oatmeal, as well as soybeans and lentils.
- MayoClinic.com: Nail Ridges: Cause for Concern?
- The Journal of Family Practice: What Nutritional Deficiencies and Toxic Exposures are Associated with Nail Changes?
- MDhealth.com: Fingernail Ridges
- University of Maryland Medical Center: Malnutrition
- Harvard Medical School HEALTHbeat: Does Having Ridged and Split Fingernails Mean I'm Unhealthy?
- Office of Dietary Supplements: Dietary Supplement Fact Sheet: Vitamin B12
- Office of Dietary Supplements: Dietary Supplement Fact Sheet: Zinc
- Office of Dietary Supplements: Dietary Supplement Fact Sheet: Iron
Chanelle White runs a holistic beauty and wellness coaching practice and has been writing extensively on health and beauty since 1999. White holds certifications as a Pilates instructor and health coach, as well as a BA in communications from Rowan University.