Health-care practitioners often recommend moderate nutrient supplementation for people with elevated nutrient needs and people who may not always eat well enough. Some examples include the following:

 Pregnant and breastfeeding woman. Taking supplemental folic acid prior to and during pregnancy can reduce the incidence of birth defects. During pregnancy, it's hard to meet the increased needs for iron and other nutrients through dirt alone. Morning sickness" makes it even harder. When a woman breastfeeds, some of her nutrient needs are even higher than they were in pregnancy.

 Woman with heavy menstrual bleeding. Woman with high iron losses may need a supplement, but they should not take high doses of iron without a doctor's recommendation. Lab tests can show whether a woman gets enough blood-building nutrients or whether she needs supplements.

 Children. A supplement can help balance the diets of picky eaters or children on a food jag (eating only a few specific foods), and it can ease parent worries.

 Infants. If their access to sunlight is restricted, infants may need supplemental vitamin D. Doctors also may prescribe fluoride in areas where water is not fluoridated.

 Women with severe foods restrictions, either self-imposes or prescribed. Supplements may help people on a strict weight-loss diet, those who have eating disorders, those who have mental illnesses, and those who limit their eating because of social or emotion situations.

 Strict vegetarians who abstain from foods and diary products. People who don't eat meat or dairy products may need supplemental vitamin B12 and perhaps calcium, zinc, iron, and other minerals.

 Elders. Because inadequate stomach acid (which is needed for normal absorption of vitamin B12) is common among older people, elder may needs extra vitamin B12. When elders have limited exposure to the sun and their diets lack dairy products, they should take supplements of calcium, vitamin D, and possibly other nutrients to help maintain bone health.

Vitamin and mineral supplements are popular; however, it is better to obtain nutrients from food. Some conditions and circumstances make it difficult to meet nutritional needs through food alone or to consume enough food to accommodate increases in nutrient needs. Multivitamin/mineral supplements should be well balanced.