Top Vitamin Deficiencies

Vitamins belong to a group of organic food components known as micronutrients. Whenever you eat a food, part of what you are taking in is vitamins. It could be vitamin C from a golden orange or a crisp red sweet pepper, B vitamins from crusty whole grain bread; or from your skin, which synthesizes vitamin D when exposed to sunlight. With so many vitamins and so many different ways to get them, if your diet is not well-balanced, it's not surprising that vitamin deficiencies can occur.

Vitamin Basics

Vitamins can be fat soluble or water soluble. Fat-soluble means the vitamin requires fat in the diet and can be stored by the body. Water-soluble vitamins are readily excreted in the urine and need to be eaten more frequently to ensure adequate serum levels. A vitamin deficiency can result if you are not eating the right types or amounts of foods, or if the food itself is deficient in a particular vitamin. Absorption problems due to disease, decreases in gastric acid or advancing age can also be a factor. Very restricted diets, such as low calorie weight loss diets, macrobiotic diets or vegan diets, can increase the risk of vitamin deficiency because certain types or amounts of foods are limited. Vitamin deficiencies usually develop slowly, particularly for the fat-soluble vitamins, because the body can store a reserve. According to Nutrition MD, a website operated by the Physicians Committee for Responsible Medicine, the most common vitamin deficiencies are vitamin B-12, vitamin C and vitamin D.

Vitamin B-12

Vitamin B-12 is a water-soluble vitamin that contains the mineral cobalt. It is needed to help form red blood cells and for proper neurological function. Deficiency occurs in 10 to 15 percent of people over the age of 60, according to NutritionMD, primarily because of poor absorption from the intestinal tract. Pernicious anemia is an autoimmune disease that can cause gastric mucosa atrophy, leading to vitamin B-12 deficiency. Symptoms of deficiency include fatigue, weakness, loss of appetite and neurological changes such as numbness of hands and feet. Recommended intake of vitamin B-12, according to the Institute of Medicine, varies from .4 mcg for infants to the age of six months up to 2.8 mcg for women who are breastfeeding. The best food sources are fish, meat, poultry, eggs, milk, and milk products. Some nutritional yeast products may also be a source of vitamin B-12, especially for vegetarians who limit animal proteins.

Vitamin C

Vitamin C cannot be synthesized by the body and must be ingested every day. Also known as ascorbic acid, it is water soluble and acts as an antioxidant. Antioxidants help protect the body from free radicals, destructive compounds formed food is converted into energy. Free radicals are also produced by cigarette smoke, air pollution, and ultraviolet light from the sun. Vitamin C is used by the body to make collagen, promote immune function and metabolize iron. Severe deficiencies cause scurvy, a disease that results in fatigue, gum inflammation and depression. While rare, scurvy can be fatal if not treated. Vitamin C is readily available from foods such as citrus, sweet red pepper, broccoli, tomatoes and kiwifruit. RDAs vary from 50 mg for infants 7 to 12 months up to 115 mg for teenagers who are breastfeeding. Smokers, according to the Office of Vitamin Supplements, should add 35 mg per day to the above requirements.

Vitamin D

Vitamin D is naturally available in some foods and added to others, such as milk. The body can also make vitamin D if the skin is exposed to sufficient sunlight. Sun exposure may be limited in far northern latitudes, by excessive use of sunscreen or if people do not spend much time outdoors. If the body has problems with fat absorption, such as occurs in some forms of liver disease, cystic fibrosis, and Crohn's disease, fat-soluble vitamins such as vitamin D may not be absorbed, and a deficiency can result. Vitamin D is necessary for calcium absorption and bone development; it also reduces inflammation. Recommended dietary allowances -- RDAs -- range from 10 mcg for infants up to one year to a high of 20 mcg for adults over the age of seventy. Natural food sources, which are limited, include fatty fish such as salmon, tuna, and mackerel; fish liver oils; beef liver; cheese, and egg yolks. Vitamin D fortified milk is commonly available, and sun exposure of 5 to 30 minutes a day allows for sufficient Vitamin D synthesis while limiting damage to the skin.

Considerations and Warnings

Vitamins are necessary to health but higher amounts are not necessarily better, and some vitamins can interfere with prescription medications. Vegetarians must be especially vigilant about dietary vitamin intakes since they restrict some classes of food. If you have questions or concerns about your vitamin intake, consult with a health care professional.