Micronutrient Calculator

Micronutrients are vitamins and minerals needed in relatively small quantities for normal metabolism, tissue maintenance, immunity, blood formation, and many other processes. Unlike carbohydrate, protein, and fat, they are not usually counted as energy sources. Their daily targets are expressed in milligrams, micrograms, or international units. This calculator presents reference intake values for vitamin D, iron, calcium, vitamin B12, folate, and zinc. These nutrients were selected because their recommended amounts vary meaningfully with age, sex, pregnancy, breastfeeding, or diet pattern and because they are commonly discussed in nutrition assessment. The estimates use adult Recommended Dietary Allowance concepts rather than a body-weight formula. Vitamin D is shown as 600 IU per day for adults through age 70 and 800 IU from age 71. Calcium is 1,000 mg for most adults, increasing to 1,200 mg for women from age 51 and all adults from age 71. Iron is 18 mg for nonpregnant women through age 50 and 8 mg for most other adults. Pregnancy increases iron to 27 mg and folate to 600 mcg dietary folate equivalents. Breastfeeding changes several values, including folate, vitamin B12, iron, and zinc. People eating vegetarian or vegan diets may absorb less iron and zinc because plant foods contain non-heme iron and compounds that can reduce mineral bioavailability. This calculator applies a factor of 1.8 to the displayed iron and zinc target when that diet option is selected. It is a planning convention, not a recommendation to take an equivalent supplement dose. Food preparation, meal composition, fortified foods, and an individual's nutritional status can all affect absorption. Vitamin C consumed with plant iron can improve absorption, while some phytate-rich foods and beverages may reduce it. Reference intakes are designed to cover nearly all healthy people in a demographic group, but they cannot determine whether a particular person is deficient. Symptoms are nonspecific, and excessive supplemental intake can also cause harm. Medical conditions affecting the gut, kidneys, liver, blood, or endocrine system may substantially change needs. Medicines and prior surgery can also affect absorption or metabolism. Use the results to compare broad dietary goals, then discuss suspected deficiency, pregnancy supplementation, restrictive diets, or high-dose products with a qualified clinician or registered dietitian. Laboratory testing and a complete dietary assessment are the appropriate tools for diagnosing and managing a deficiency.