FatCalc

Micronutrient Calculator

How much vitamin D, iron, or magnesium do you need each day? Enter your sex and age, and this calculator lists your daily target for every vitamin and mineral, along with the upper limit not to exceed and the foods richest in each. The targets are the official Dietary Reference Intakes used in the United States and Canada, adjusted for pregnancy, breastfeeding, a vegetarian or vegan diet, and smoking.

Micronutrient Calculator
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Select your sex and enter your age to see your daily vitamin and mineral targets.

This micronutrient calculator gives you the daily amount of each vitamin and mineral recommended for your sex, age, and life stage. It covers all 13 vitamins plus choline, and 14 minerals, from calcium and iron to trace elements such as selenium and molybdenum, followed by the two essential fatty acids, omega-3 and omega-6. Beside each target you'll find the Tolerable Upper Intake Level, the most you can take every day without risk of harm, and a few of the best food sources. The calculator covers ages 14 and up. Your entries are saved in your browser for your next visit.

How to Use the Micronutrient Calculator

  1. Choose your sex and enter your age. Most targets change at 19, 31, 51, and 71.
  2. If you're female and aged 14 to 50, say whether you're pregnant or breastfeeding. These change more targets than anything else.
  3. Choose your diet. A vegetarian or vegan diet raises the iron target and adds notes on zinc, B12, iodine, and calcium.
  4. Tick I smoke if you do. Smokers need 35 mg more vitamin C a day.

The results update as you go. Targets marked with an asterisk are Adequate Intakes rather than Recommended Dietary Allowances, and any note under a nutrient explains an adjustment or a recommendation that applies to you.

RDA, AI, and Upper Limit Explained

The targets come from the Dietary Reference Intakes (DRIs), set by the Food and Nutrition Board of the National Academies of Sciences, Engineering, and Medicine (the earlier reports were published under the Institute of Medicine) and used by both the United States and Canada. For each nutrient and life stage group, an expert panel reviews the evidence and sets up to three numbers that matter to you:

  • Recommended Dietary Allowance (RDA): the daily intake that meets the needs of 97 to 98% of healthy people in the group. Most people need less, so falling a little short on one day is no cause for concern.
  • Adequate Intake (AI): used when the evidence isn't strong enough for an RDA. It is based on the intakes of healthy people and is assumed to be enough for almost everyone.
  • Tolerable Upper Intake Level (UL): the highest daily intake unlikely to cause harm in almost anyone. It is a ceiling, not a goal, and there is no benefit to getting close to it.

"Not set" in the upper limit column means there wasn't enough data to set a UL, not that any amount is safe. Large doses of any nutrient should be taken only with medical advice.

Why Your Weight Doesn't Matter Here

Unlike Calories or protein, vitamin and mineral targets are not scaled to body size. The DRIs are set for groups defined by sex, age, and pregnancy or breastfeeding, and the same targets apply to a small woman and a large one of the same age. That is why the calculator doesn't ask for your weight or height. The life stage bands do matter: calcium rises from 1,000 mg to 1,200 mg at 51 for women and at 71 for men, vitamin D rises from 15 mcg to 20 mcg at 71, and a woman's iron target falls from 18 mg to 8 mg at 51, when periods have usually stopped.

Pregnancy and Breastfeeding

Pregnancy raises the targets for most vitamins and minerals. The biggest changes are in iron, which rises to 27 mg a day to supply the extra blood volume and the baby, folate, which rises to 600 mcg, and iodine, which rises to 220 mcg. Breastfeeding raises the vitamin A, vitamin C, zinc, and iodine targets further still, while iron falls back to 9 or 10 mg because periods usually haven't returned yet.

Because many pregnancies are unplanned and the neural tube forms in the first weeks, the CDC advises everyone who could become pregnant to take 400 mcg of folic acid a day, from a supplement or fortified food, on top of the folate in a normal diet. The American Thyroid Association also recommends a daily supplement containing 150 mcg of iodine for anyone who is pregnant, planning a pregnancy, or breastfeeding. Check your prenatal vitamin's label: nearly all contain folic acid, but studies of US prenatal vitamins have found that only about half contain iodine.

Vegetarian and Vegan Diets

The iron in plant foods (non-heme iron) is absorbed less well than the heme iron in meat and fish. For that reason, the DRI panel set the iron requirement for vegetarians at 1.8 times the standard amount, which the calculator applies when you choose a vegetarian or vegan diet. Eating vitamin C-rich foods with plant sources of iron, and avoiding tea or coffee with meals, helps absorption. Zinc needs may also be up to 50% higher, for a similar reason.

Vitamin B12 is found naturally only in animal foods, so vegans need fortified foods or a supplement to meet the 2.4 mcg target. Vegan diets can also run short of iodine, calcium, and vitamin D. Iodized salt, calcium-set tofu, fortified plant milks, and a vitamin D supplement in winter fill those gaps.

Supplements and Upper Limits

For most vitamins and minerals it is hard to go over the upper limit with food alone. The exceptions are a few very rich foods, such as liver for vitamin A and Brazil nuts for selenium, and sodium, which most people already eat too much of. Some upper limits count only certain sources for that reason. The magnesium UL of 350 mg applies only to supplements and medicines; magnesium from food doesn't count toward it. The folate UL counts only the folic acid in supplements and fortified foods, the vitamin A UL counts only preformed vitamin A (retinol), not the beta-carotene in plants, and the vitamin E and niacin ULs apply only to supplements and fortified foods.

The risk comes from supplements, and from stacking them. A multivitamin, a separate vitamin D, and a fortified breakfast cereal can add up quickly. Before you add a supplement, compare its label to the upper limits in your results, remembering to allow for what you get from food. People over 50 are the exception the other way: the DRI panel advises getting most of your B12 from fortified foods or a supplement, as absorption from food declines with age.

Sodium and Potassium

Sodium is the one nutrient on this list that most people need to eat less of. The target of 1,500 mg a day is the amount healthy people need, while 2,300 mg is the Chronic Disease Risk Reduction intake: above it, cutting back lowers the risk of high blood pressure and heart disease. According to the FDA, more than 70% of the sodium Americans eat comes from packaged and prepared foods rather than the salt shaker, led by deli meat sandwiches, pizza, burritos and tacos, and soups. Potassium works the other way: average intakes in the US fall short of the target of 2,600 mg for women and 3,400 mg for men. Fruit, vegetables, beans, and potatoes are the best sources.

Omega-3 and Omega-6 Fats

Omega-3 and omega-6 are not micronutrients: they are fats, needed in grams rather than milligrams, and they supply 9 Calories per gram like any other fat. They appear in the results because they are essential. Your body can't make them, so they have to come from food, just like vitamins and minerals. The targets are the Adequate Intakes for alpha-linolenic acid (ALA), the omega-3 in flaxseed, chia, walnuts, and canola oil, and linoleic acid, the omega-6 in most vegetable oils.

Your body converts only a small share of ALA into EPA and DHA, the long-chain omega-3s found in oily fish such as salmon, sardines, and mackerel. The US and Canadian DRIs set no target for EPA and DHA, but the European Food Safety Authority sets 250 mg a day for adults, about one or two servings of oily fish a week, plus 100 to 200 mg of DHA during pregnancy and breastfeeding. Algae oil supplies EPA and DHA for people who don't eat fish. Omega-6 is rarely short in Western diets, which get plenty of linoleic acid from cooking oils and processed foods.

Food First

A varied diet with plenty of vegetables, fruit, whole grains, beans, nuts, dairy or fortified alternatives, and fish or lean meat meets most of these targets without much planning. The Dietary Guidelines for Americans name calcium, potassium, vitamin D, and fiber as the nutrients Americans most often fall short of, and iron as a concern for teenage girls and women before menopause, including during pregnancy. If you set your daily Calories with the TDEE Calculator for All Ages and split them with the Macro Calculator, these targets are the next step: making sure the food inside those macros is nutritious.

Other Countries' Recommendations

These are the US and Canadian values. The European Food Safety Authority, the UK, Australia and New Zealand, and the World Health Organization set their own reference values, which are similar for most nutrients but can differ by a quarter or more for a few, such as vitamin C and calcium. If you follow advice from your own country's health service, use its numbers. The DRIs assume healthy people; if you have a medical condition or take medication that affects nutrient needs, your doctor's advice comes first.

Frequently Asked Questions about Vitamins and Minerals

The Recommended Dietary Allowance (RDA) is the daily amount that meets the needs of 97 to 98% of healthy people of your sex and age. When there isn't enough evidence to set an RDA, an Adequate Intake (AI) is set instead: an amount that appears to be enough, based on what healthy people eat. The Tolerable Upper Intake Level (UL) is the most you can take every day with no likely risk of harm. The targets marked with an asterisk in the results are AIs.
Because the official targets don't depend on them. The Dietary Reference Intakes are set for groups by sex, age, and pregnancy or breastfeeding, and a 55 kg woman and a 95 kg woman of the same age get the same targets. A calculator that asked for your weight would give you the same list whatever you typed. The things that do change a number are asked for: your age band, pregnancy, a vegetarian diet (iron), and smoking (vitamin C).
Most healthy people who eat a varied diet can meet these targets from food. Supplements are recommended for specific groups: folic acid for anyone who could become pregnant, iodine during pregnancy and breastfeeding, B12 from fortified foods or a supplement for vegans and people over 50, and often vitamin D for people who get little sun. If you take one, check that it doesn't push any nutrient past its upper limit once your food is added.
An occasional day over the UL is not dangerous, but the risk of harm rises the longer and further you stay above it. It is hard to get there from food alone; most people who exceed a UL do it with supplements, often by taking several that contain the same nutrient. For some nutrients the UL only counts certain forms: magnesium from supplements, folic acid rather than food folate, and preformed vitamin A rather than beta-carotene.
The DRIs don't set separate values for athletes, and the extra food that active people eat usually supplies the small extra needs. The exceptions are sodium, which you lose in sweat during long or hot sessions, and iron, which endurance athletes, especially women, are more likely to run low on. A blood test is a better guide than guesswork if you suspect low iron.
No. Omega-3s are fats, which makes them part of the fat macronutrient: you need them in grams rather than milligrams, and they supply 9 Calories per gram. They are often grouped with vitamins because they are essential, meaning your body can't make them and they must come from food. That is why the calculator lists them in a separate Essential Fatty Acids table after the minerals. The target is for ALA, the plant omega-3; EPA and DHA from fish have no US target, though the European Food Safety Authority sets 250 mg a day for adults.
The official values are in micrograms, but many supplement labels still use International Units. For vitamin D, 1 mcg equals 40 IU, so the 15 mcg target for most adults is 600 IU and the 100 mcg upper limit is 4,000 IU.
They are units that put different forms of a vitamin on the same scale. Retinol activity equivalents (RAE) count beta-carotene from plants at 1/12 the strength of retinol. Dietary folate equivalents (DFE) count folic acid taken with food as 1.7 times stronger than natural food folate, because it is absorbed better. Niacin equivalents (NE) count the niacin your body makes from tryptophan, at 60 mg of tryptophan for 1 mg of niacin.
The Daily Value on US labels is one figure for everyone aged 4 and older, usually the highest target of any group, so that the label works for everyone. Iron, for example, has a Daily Value of 18 mg, the target for women of 19 to 50, while men need only 8 mg. The targets in this calculator are the ones for your own group.

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Further Reading:

  1. The Institute of Medicine's Dietary Reference Intakes: The Essential Guide to Nutrient Requirements (2006) explains how RDAs, AIs, and ULs are set, with a chapter on each vitamin and mineral. View
  2. The Institute of Medicine's Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc (2001) is the source of the 1.8 times higher iron requirement for vegetarians. View
  3. The Institute of Medicine's Dietary Reference Intakes for Calcium and Vitamin D (2011) set the current calcium and vitamin D targets and upper limits. View
  4. The National Academies of Sciences, Engineering, and Medicine's Dietary Reference Intakes for Sodium and Potassium (2019) set the potassium targets and the 2,300 mg chronic disease risk reduction intake for sodium. View
  5. The Institute of Medicine's Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (2005) set the Adequate Intakes for the essential fatty acids, alpha-linolenic acid (omega-3) and linoleic acid (omega-6). View
  6. The European Food Safety Authority's Scientific Opinion on Dietary Reference Values for fats (2010), published in the EFSA Journal, sets an Adequate Intake of 250 mg a day of EPA plus DHA for adults. View
  7. Health Canada's Dietary Reference Intakes table of reference values for vitamins lists the targets and upper limits for every life stage group, with footnotes on which forms each upper limit applies to. View
  8. Health Canada's table of reference values for elements gives the same for the minerals, including the sodium chronic disease risk reduction intake. View
  9. Health Canada's table of reference values for macronutrients lists the Adequate Intakes for the essential fatty acids, linoleic acid and alpha-linolenic acid. View
  10. The NIH Office of Dietary Supplements fact sheets cover each vitamin and mineral's functions, food sources, deficiency, and interactions with medicines. View
  11. The US Food and Drug Administration's Sodium in Your Diet page explains that most sodium comes from packaged and prepared foods and lists the foods that, according to the CDC, supply about 40% of the sodium Americans eat. View
  12. The Linus Pauling Institute at Oregon State University's article on essential fatty acids lists the food sources of linoleic acid (omega-6) and alpha-linolenic acid (omega-3), which have no NIH fact sheet of their own. View
  13. The CDC's clinical overview of folic acid sets out why everyone who could become pregnant should take 400 mcg of folic acid a day. View
  14. The 2017 guidelines of the American Thyroid Association for thyroid disease during pregnancy and the postpartum, by E.K. Alexander, E.N. Pearce, G.A. Brent, and colleagues, published in Thyroid, recommend a daily 150 mcg iodine supplement during pregnancy and breastfeeding. View