There is much truth to the old adage, 'you are what you eat.' Immune function is related to nutritional intake—and inadequate daily vitamins can lower immunity. For persons who are HIV-positive, cancer survivors, or organ transplant recipients, the immune system needs extra attention because it has been damaged. Healthy eating boosts immunity to infection, which can prevent catching head colds, influenza, and gastrointestinal viruses from others around you.
Function of the Immune System
The purpose of the immune system is to protect the body (as host) from invasion by microbial invaders. Bone marrow is the site of white blood cell (leukocyte) creation—essential for the immune system to function properly. Micronutrient deficiencies in Vitamins A, B6, C, and E have been linked to lowered immune function (as well as deficiencies in zinc, selenium, iron, copper, and folic acid), per the Harvard Health Letter—but boosting intake of one vitamin is not the solution. Instead, a nutritious diet, supplemented by a daily vitamin with minerals, is the best choice.
Poor nutrition can wreak havoc on the protective ability of the immune system—as can recurrent infections, radiation, chemicals, and pharmaceutical agents. Lack of specific vitamins and minerals can weaken the physiological systems that support immunity (and some drugs actually cause specific vitamins to become depleted).
Five Vitamins and Minerals Supporting Immunity
Vitamin D is necessary for proper bone development—and is found in high amounts in dairy products. While most people get enough dietary Vitamin D in the U.S., this can be a problem for people who are lactose-intolerant. According to the American Cancer Society, the use of laxatives may lower the absorption of Vitamin D (so a supplement may be warranted).
The “B” vitamins are recognized to affect immune function, along with the enzymes that regulate biochemical reactions. Vitamin B6 is related to the development of red blood cells—so a deficiency can result in anemia. The “B” complex of vitamins are called B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6, B7 (biotin), B12, and folic acid. Each of the constituents of the “B” group of vitamins needs to be taken in a balanced proportion to each other.
Vitamin C is involved in the repair and maintenance of cartilage, and absorption of iron. Since iron is essential for healthy red blood cells, Vitamin C plays a role in boosting immune function. However, medical research is inconclusive as to whether large doses of Vitamin C actually aid immunity.
Vitamin E has anti-oxidant properties, and may be protective against free radicals (which have been implicated in causing cellular mutations leading to cancer). Vitamin E is also important in the absorption of Vitamin K. It is found in most green leafy vegetables, nuts, fortified breakfast cereals, and vegetable oils (according to the National Institutes of Health).
Iron is a mineral that is fundamental to proper immune function. Since it is found in high quantities in red meat, a poorly-planned vegetarian diet can lead to anemia. Dried fruits can supplement the lowered iron intake in such diets. Iron-deficiency anemia is related to poor immunity against infections. However, too much iron intake can be harmful to health.
Rather than supplements in pill form, a well-balanced diet and daily exercise is the best way to boost your immune system.