Vitamins and minerals, explained

Here's how much of each vitamin and mineral we should aim for every day (from foods and supplements combined), according to the new Daily Values (DVs) set by the Food and Drug Administration. The DVs are based on the National Academy of Medicine’s Recommended Dietary Allowances (RDAs), which vary slightly by age and sex.

The FDA updated the DVs in 2016, but labels didn't have to start using the new DVs until 2020 or (for small companies) 2021.

New Daily Values (DVs)

• Vitamin A: 900 mcg
• Vitamin D: 20 mcg (800 IU)
• Thiamin (Vitamin B-1): 1.2 mg
• Riboflavin (Vitamin B-2): 1.3 mg
• Niacin (Vitamin B-3): 16 mg
• Vitamin B-6: 1.7 mg
• Vitamin B-12: 2.4 mcg
• Biotin: 30 mcg
• Pantothenic Acid: 5 mg
• Iron: 18 mg
• Magnesium: 420 mg
• Selenium: 55 mcg
• Chromium: 35 mcg
• Iodine: 150 mcg
• Manganese: 2.3 mg
• Molybdenum: 45 mcg
• Chloride: 2,300 mg
• Boron: DV not established
• Vitamin C: 90 mg
• Vitamin E: 15 mg
• Vitamin K: 120 mcg
• Folate: 400 mcg DFE (235 mcg Folic Acid)
• Calcium: 1,300 mg
• Phosphorus: 1,250 mg
• Zinc: 11 mg
• Copper: 0.9 mg
• Potassium: 4,700 mg
• Choline: 550 mg
• Nickel: DV not established
• Silicon: DV not established
• Tin: DV not established
• Vanadium: DV not established

What else you should know

Vitamin A

Most multivitamins contain some mix of retinol (vitamin A) and beta-carotene (which our bodies convert to retinol). The DV dropped from 5,000 IU to 3,000 IU, but new labels list the new DV in micrograms (900 mcg). More than 10,000 IU (3,000 mcg) a day of retinol from supplements can cause birth defects if taken by pregnant women. High doses of beta-carotene (25,000 to 50,000 IU a day) raise the risk of lung cancer in smokers and, possibly, former smokers.

Vitamin D

The DV doubled, from 400 IU to 800 IU (20 mcg). Our bodies make vitamin D from sunlight, and it’s added to most milk, some breakfast cereals, and some yogurts. A large trial found that vitamin D doesn’t prevent cancer, heart disease, or stroke. Results on memory, asthma, autoimmune disease, and more are expected soon. Taking more than 4,000 IU (100 mcg) a day may lead to dangerously high blood levels of calcium.

Thiamin (B-1), Riboflavin (B-2), Niacin (B-3), and Vitamin B-6

The DVs for these B vitamins dropped slightly. Way-above-the-DV doses are useless but probably safe. Exceptions: levels over 35 milligrams of niacin from supplements can cause flushing of the skin and more than 100 mg of B-6 can cause (reversible) nerve damage and skin lesions.

Vitamin B-12

The DV dropped from 6 micrograms to 2.4 mcg. Adults over 50 should get most of their 2.4 mcg from a supplement or fortified foods because they may not make enough stomach acid to digest and absorb B-12 from meat, eggs, and dairy. People who take acid blockers or metformin or who eat no animal foods may also have low levels. A B-12 deficiency can cause irreversible nerve damage that can masquerade as dementia.

Biotin and Pantothenic Acid

Both are superfluous in supplements. We get plenty from our food.

Iron

Premenopausal women, who lose iron through menstruation, should get the DV (18 milligrams). Men and postmenopausal women need only 8 mg. More isn’t better, because there’s no easy way to know if you have genes that lead your body to store excess iron (hemochromatosis), which may raise your risk of cirrhosis, liver cancer, or diabetes.

Magnesium

The DV increased from 400 milligrams to 420 mg. About half of all Americans get too little, which may raise the risk of type 2 diabetes. Leafy greens, beans, whole grains, and nuts are the best sources. Few multis have more than 100 mg. Many have less. More than 350 mg from supplements (but not foods) can cause diarrhea and stomach cramps.

Selenium

The DV dropped from 70 micrograms to 55 mcg. Americans average about 100 mcg a day from their food. Whether selenium supplements increase the risk of type 2 diabetes and prostate cancer is still unclear, so stick to a multi with no more than about 55 mcg.

Chromium

The DV dropped from 120 micrograms to 35 mcg. If you have type 2 diabetes, don’t expect chromium to lower your blood sugar or boost your metabolism.

Iodine, Manganese, Molybdenum, Chloride, and Boron 

The Centers for Disease Control and Prevention warns that many women in their 20s and 30s may not be getting enough iodine, which the developing brain needs during pregnancy. Milk, yogurt, and seafood are good sources. We get plenty of the other four minerals from our food.

Vitamin C

The DV rose from 60 milligrams to 90 mg. Many Americans get too little vitamin C from their food. Smokers need 125 mg a day because smoking creates extra cell-damaging free radicals. Taking more than 1,000 mg a day may cause kidney stones in men, and more than 2,000 mg a day may cause diarrhea in men and women.

Vitamin E

The DV dropped from 30 IU to 15 milligrams, which is equal to 22.4 IU. High doses of vitamin E may not be safe. In a large trial, men who took 400 IU a day for 5½ years had a 17 percent higher risk of prostate cancer. To play it safe, look for a multi with no more than 80 IU. Good food sources include nuts, oils, and leafy greens.

Vitamin K

The DV jumped from 80 micrograms to 120 mcg. Most multivitamins have less because vitamin K can interfere with blood-thinning drugs like warfarin (Coumadin). If you’re taking a blood thinner, check with your doctor about adjusting the dose before you start (or stop) taking a multivitamin with vitamin K. Leafy greens are the best food source.

Folate

The new DV is 400 micrograms DFE (Dietary Folate Equivalents), but supplements will also list the old units (micrograms, or mcg). The DFE accounts for our ability to absorb the folic acid that is added to supplements and fortified foods better than the folate that occurs naturally in foods.

CAUTION: Women who could become pregnant should take a supplement with 400 mcg of folic acid (680 mcg DFE) to reduce the risk of birth defects like spina bifida, which can occur before a woman knows that she is pregnant. If a multi has 100% of the new DV, that’s equal to 235 mcg of folic acid, so it’s not enough.

Calcium

The DV rose from 1,000 milligrams to 1,300 mg. That’s based on what children aged 9 to 18 need. Premenopausal women and men up to age 70 need 1,000 mg. Postmenopausal women and men over 70 need 1,200 mg. Many multivitamins have 200 to 300 mg (some have far less). That may be enough to get you to the DV, since each serving of milk, yogurt, cheese, or fortified foods has 150 to 300 mg, and most people get 250 mg from the rest of their diet. Taking a daily supplement with 1,000 mg or more may raise the risk of kidney stones. Getting 2,000 mg or more may raise the risk of prostate cancer.

Phosphorus

The DV is 1,250 milligrams. Most people get plenty from meat, poultry, grains, dairy, and the phosphates and phosphoric acid in processed foods. Too much phosphorus may raise the risk of heart and kidney disease. Look for a multi with little or none.

Zinc and Copper

The DV for zinc dropped from 15 milligrams to 11 mg, and the DV for copper dropped from 2 mg to 0.9 mg. Too much zinc (more than 40 mg from food and supplements combined) can make it harder to absorb copper.

Potassium

The DV, which rose from 3,500 milligrams to 4,700 mg, is already outdated. The most up-to-date recommendations: 3,400 mg for men and 2,600 mg for women. Potassium can help lower blood pressure, but a typical multi has only 80 mg. Your best sources: fruits and vegetables. Orange, anyone?

Choline

Pregnant women need 450 milligrams a day, but even prenatal supplements typically supply little or none.

Nickel, Silicon, Tin, and Vanadium

It’s not even certain that we need them.