Drugs readily available without prescription also can lead to nutritional problems. The worst offenders are antacids, Dr. Roe says, because they are so widely abused by the public. Chronic use of these remedies without a doctor’s supervision can cause phosphate depletion, a condition that in its milder form produces muscle weakness and in more severe form leads to a vitamin D deficiency. “Unfortunately,” says Dr. Roe, “some people get into the habit of taking enormous amounts of these drugs to treat gastric upset that in itself is due to their abuse of some other substance, such as alcohol, coffee, or food.”
Mineral oil, an old-fashioned laxative still widely used by elderly people and in nursing homes, can hinder absorption of vitamin D. One study reported that as little as 20 milliliters (4 teaspoons) of mineral oil twice daily can interfere with absorption of vitamin D, vitamin K, and carotene, a substance the body converts to vitamin A.
Don’t be afraid to ask how drugs might interact with your favorite edibles, especially if you consume large amounts of certain foods and beverages. While taking drugs, be sure to tell your doctor about any unusual symptoms that follow eating particular foods. If you are eating a nutritionally well-balanced diet from a wide variety of foods, use of a needed drug, even on a long-term basis, is less likely to cause depletion of vitamins and minerals.