Table of Contents
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Click the icon to see an image of sources for vitamin C. |
Alcoholics. Alcoholics often have multiple vitamin deficiencies. The most dangerous deficiencies are in vitamins B1 (thiamin), folic acid, B6 (pyridoxine), B2 (riboflavin), and vitamin C. Low levels of vitamin B6 are associated with an increased risk for colorectal cancer in men who drink large amounts of alcohol.
People Who Have Had Gastric Bypass Surgery. Vitamin deficiency is a recognized complication of gastric bypass surgery. Women, African Americans of both sexes, and adults who have had laparoscopic Roux-en-Y bypass surgery are at highest risk. The deficiency is treated with water-soluble vitamin supplements.
Strict Vegetarians. Strict vegetarians need supplements of vitamin B12, unless they get enough of it from fortified cereals and other grain products.
Dieters and Vegetarians. People on weight-reduction diets of fewer than 1,000 calories a day should probably take a multivitamin, and should also check regularly with a physician.
Vegetarians may need riboflavin, vitamin B12, and vitamin D supplements. Vegans, who do not eat dairy or eggs as well as meat, may be at further risk for vitamin A deficiencies if they do not also eat plenty of dark-colored fruits and vegetables. Those who eat eggs and dairy products need to only watch their iron levels.
Deficiencies in vegetarian children may be particularly harmful. Pregnant and breast-feeding women who are vegetarians must be sure to have sufficient vitamins. Of special note, maternal deficiencies in vitamin B12 may cause delayed growth and neurologic problems in newborns.
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Click the icon to see an image of sources for vitamin D. |
Older Adults. Deficiencies of vitamins and important minerals have been observed in almost a third of elderly people. Often their dietary habits slip and they fail to eat balanced meals regularly. In addition, older adults are more likely to be taking medications for a variety of conditions. Multiple drug regimens may prevent absorption of some vitamins. Elderly people, particularly if they are not exposed to sunlight, may be deficient in vitamin D. New recommendations from the International Osteoporosis Foundation advise that older adults get 800 to 1,000 IU of vitamin D a day. People who are obese, or who have osteoporosis, limited sun exposure, or poor nutrient absorption may need to increase their intake to as much as 2,000 IU per day. Seniors also may have low levels of important B vitamins. (Older adults showing signs of dementia should be checked for B12 deficiencies, as well as for other disorders that cause mental disturbances.) It should be noted, however, that metabolism slows down as a person ages, and in elderly people it takes the liver longer to eliminate drugs and vitamins from the body. The effect of some vitamin supplements, therefore, may be intensified. Dosage levels of vitamin A, for instance, which might be harmless in a younger adult, could be toxic in an elderly patient.
People Who Avoid Sunlight. People who avoid sunlight or who are housebound, and whose diet is low in foods that contain vitamin D should take supplements. People with darker skin are at higher risk for deficiencies than those with whiter skin. (Note: Vitamin D is toxic in high doses, and no one should exceed the recommended dietary intake of vitamin D except under the direction of a physician.)
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Review Date: 10/08/2010
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine,
Harvard Medical School; Physician, Massachusetts General Hospital.
Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M.,
Inc.
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)
