Why Are My Vitamins & Minerals Low?

The human body needs 13 essential vitamins -- organic compounds -- and more than 20 essential minerals -- inorganic elements -- to grow and develop. Although synthetic supplements can provide the daily recommended amount of each vitamin and mineral, the Dietary Guidelines for Americans 2010 recommends eating nutrient-dense foods to meet your vitamin and mineral intake while staying within your calorie needs. The level of vitamins and minerals in your body can become low due to a decreased intake or as a result of factors affecting the absorption.

Decreased Intake

Many Americans consume too few fruits, vegetables, whole grains and low-fat milk products. These foods all provide many essential vitamins and minerals while keeping the calorie count low. This causes a deficiency in many nutrients including potassium, calcium and vitamin D. To avoid suffering from low levels of vitamins and minerals, the Dietary Guidelines for Americans 2010 suggest increasing your intake of fruits and vegetables, especially dark green vegetables and red or orange fruits and vegetables. In less-developed countries, many children and adults suffer from malnutrition due to the lack of food available. In the United States, malnutrition too often occurs due to poor food choices instead of lack of food.

Intestinal Conditions

The human body absorbs vitamins and minerals through the lining of the small intestine. Conditions that affect the small intestine can interfere with nutrient absorption and cause the levels to become low. An autoimmune disease known as celiac disease occurs when the cells of the immune system mistakenly attack the cells of the small intestine in response to the protein known as gluten found in wheat, rye and barley. This causes inflammation of the lining of the small intestine, which inhibits the absorption of vitamins and minerals. Other intestinal disorders like Crohn's disease and irritable bowel syndrome can also cause chronic inflammation of the small intestine and interfere with nutrient absorption, leading to deficiencies.

Vitamin-Vitamin Interactions

Taking certain vitamins at the same time or taking too much of a vitamin can interfere with the absorption of another vitamin or mineral. Taking too much vitamin A, a vitamin important for the production of healthy red blood cells, can interfere with the absorption of vitamin K, a vitamin vital to the production of enzymes that promote blood coagulation. A zinc deficiency can interfere with the absorption or use of vitamin A. Because the body needs vitamin D to promote the absorption of calcium, a vitamin D deficiency reduces the amount of calcium in the body. Although the two minerals calcium and phosphorus work together to build strong bones, consuming too much phosphorus may decrease the absorption of calcium.

Vitamin-Medication Interactions

Taking certain medications can interfere with the absorption of vitamins or minerals. Medications that interfere with the absorption of fats, including cholestyramine, colestipol, isoniazid, mineral oil, orlistat and sucralfate, can interfere with the absorption of fat-soluble vitamins like vitamin E and vitamin D. Taking nonsteroidal anti-inflammatory medications like aspirin decreases the amount of vitamin C in the body. Barbiturate medications like phenobarbital can also interfere with the absorption and effectiveness of vitamin C and calcium. Corticosteroid medications including prednisone reduce the absorption of calcium and the effectiveness of vitamin D.