In healthy people, dietary supplements can help prevent vitamin and mineral deficiencies if the diet does not provide all the necessary nutrients. They can also provide quantities of nutrients that are greater than what the diet can provide. Larger amounts of some nutrients can help protect against future illnesses. Many of these nutrients will be briefly discussed here. However, you will find more information in the individual nutrient articles.
People may be on diets that are deficient in one or more nutrients for a variety of reasons. The typical Western diet often provides less than adequate amounts of several essential vitamins and minerals.1 Recent nutritional studies in the USA have shown that many people do not get enough calcium, magnesium, iron, zinc and possibly copper and manganese.
Weight loss, purely vegetarian, macrobiotic and various other diets can also put some people at risk of deficiencies, which vary depending on the type of diet. Certain groups of people have a particularly high risk of malnutrition. Studies have shown that older people who live at home often have deficiencies of vitamin D, vitamin A, vitamin E, calcium and zinc4 and occasionally vitamin B1 and vitamin B2. Premenopausal women have been found to have low levels of calcium, iron, vitamin A and vitamin C.