Quick answer

The sources we use name no best time of day. What matters more is taking it with a meal: vitamin D is best absorbed with some fat, calcium carbonate with food, and food eases the stomach upset iron can cause. Folic acid is the exception, at about 85% absorbed with food against nearly 100% without.^1,2,3,4

Key facts

Calcium is absorbed best in amounts of 500 mg or less at a time.²
Calcium citrate is absorbed well with or without food, while calcium carbonate is absorbed best with it.²
Taking nicotinic acid, a form of niacin, with food lessens the flushing it can cause.⁵
Some antibiotics and levothyroxine should be kept apart from multis that contain minerals; a pharmacist can tell you by how much.^6,7

Why a meal matters more than the clock

Vitamin D is fat soluble, so it is best absorbed with a meal or snack that includes some fat.¹

Calcium carbonate is absorbed best when taken with food, while calcium citrate is absorbed well on an empty or a full stomach.²

High doses of iron can upset the stomach, and taking iron supplements with food can help keep that to a minimum.³

Taking nicotinic acid, a form of niacin, with food can lessen the flushing it causes.⁵

Put together, a meal with some fat in it is the most forgiving moment for a multi. It suits vitamin D, which is fat soluble, it suits calcium carbonate, one of the two main forms of calcium in supplements, and it is kinder to the stomach.^1,2

About 85% of folic acid is absorbed when it is taken with food, and nearly 100% when it is taken without food.⁴

That small loss is already built into how folate is labeled. Labels list folate in dietary folate equivalents, a unit that counts folic acid as if it were taken with food.⁴

Morning or night?

Neither NIH's multivitamin fact sheets nor the nutrient sheets behind this page name a best hour. So pick the meal you are least likely to skip, and keep to it, because a multi you forget does nothing.^8,9

If a multi makes you queasy at breakfast, moving it to a larger meal later in the day is a sensible switch, since food is what eases the stomach. If the label names a time, follow the label.³

For women

Multis made for women often carry 18 mg of iron, the full Daily Value. Iron can unsettle the stomach, so these are the multis where taking them with a meal matters most.³

The body absorbs calcium best in amounts of 500 mg or less at one time.²

If you also take a calcium supplement, take it at a different meal from the multi so that neither dose goes far beyond 500 mg at once.²

For women who could become pregnant, the 400 mcg of folic acid a day matters more than the hour it is taken. A daily habit is the point.¹⁰

For men

Multis for men often contain less iron or none, which leaves the meal rule mainly about absorbing vitamin D and calcium. Our Men's Multi's label says to take two capsules in the morning with a meal.^1,3

What’s in ours

Men's Multi: Vitamin A, 600 mcg RAE per serving, from the label

Spacing a multi from medicines

Ask your pharmacist how far apart to take them

Two groups of antibiotics, quinolones such as ciprofloxacin and levofloxacin and tetracyclines such as doxycycline, can bind to calcium, magnesium, iron or zinc, so less of the antibiotic is absorbed. The ciprofloxacin and levofloxacin labels name multivitamins among the products that can keep the antibiotic from working correctly, and NIH says zinc, calcium and magnesium supplements interact with these antibiotics.^{2,6,11,12,13,14}

On the medicine's label

Ask your pharmacist how far apart to take them

Calcium and iron can reduce how much levothyroxine is absorbed. The levothyroxine label tells patients that iron and calcium supplements can decrease its absorption, and MedlinePlus names calcium carbonate and iron supplements, and also niacin, among products that may interact with it. Many multivitamins contain calcium, and some contain iron.^2,3,7,15

On the medicine's label

These are the cases where the time of day matters most, and the right gap depends on the medicine. Ask your pharmacist how far apart to take them rather than guessing.

Biotin above recommended amounts can cause falsely high or falsely low results on some lab tests, including thyroid hormone tests. The levothyroxine label tells people to stop biotin supplements before thyroid testing.^7,16

Questions people ask

Should I take my multivitamin at night?

You can, if that is when you eat a meal and will remember it. The sources behind this page give no reason to prefer morning or night, and taking it with food matters more.^1,2

Can I take a multivitamin on an empty stomach?

You can, but you may absorb less vitamin D and calcium carbonate, and any iron in it is more likely to upset your stomach. Folic acid is the one nutrient absorbed slightly better without food.^1,2,3,4

See what we make

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See the Full Measure line Men's Multi

Sources

This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.