best time to take vitamins



The best time to take many vitamins and minerals is in the morning, with a meal. However, there are a few supplements that may help you sleep better when taken shortly before bedtime. Therefore, the best time for you to take your vitamins will depend on exactly which vitamins you’re taking, and on the health effects that you hope to gain from taking them.

Vitamins that may be better when taken in the morning include:

  • Vitamin C
  • Certain B vitamins
  • Vitamin D

Vitamins and supplements that may be better when taken in the evening, close to bedtime, include:

  • Vitamin B-3 (niacin)
  • Magnesium

Some people find that vitamins and minerals can cause upset digestion and even diarrhea if taken on an empty stomach. Therefore, it’s generally better to take vitamin and mineral supplements with a meal, unless you’re advised differently by your doctor.

To complicate matters further, certain vitamins need to be taken in combination with a meal that contains some fat calories. That’s because they’re “fat-soluble,” which means they only dissolve—and are absorbed properly by your body—when you take them along with some fat. Therefore, if you take your vitamins in the morning with a largely fat-free breakfast (perhaps fat-free cereal topped with skim milk), you could be defeating the purpose of consuming the vitamins.

Here’s a rundown of the best times to take specific vitamins and minerals, the best time to take multivitamins, and which supplements should be taken along with some fat calories.

  • Vitamin A

Vitamin A helps to maintain your vision, organs, and reproductive system. There’s no evidence that it’s better to take vitamin A in the morning or in the evening, so take your vitamin A supplement whenever it’s most convenient for you. The type of vitamin A found in most supplements is beta-carotene.

Vitamin A and beta-carotene both are fat-soluble, so that means you need to take them with a source of fat. In most cases, this means taking your vitamin A with a meal, and in fact, many manufacturers of vitamin A supplements recommend taking the products with a meal.

  • B Vitamins

B vitamins—which include thiamine, folic acid, and riboflavin—help your body function properly and stay healthy. When your levels of certain B vitamins are too low, you might find that you’re more tired than you should be. Confusion and anemia also can occur in severe cases, depending on which B vitamins you’re lacking.

Most people take B vitamins as a group, either in a multivitamin capsule or in a specific B vitamin supplement. Although they’re water-soluble, it’s best for your digestion to take them with a meal, and you may find it’s easiest to remember to take them in the morning with breakfast.

There’s a little evidence that certain B vitamins can interfere with sleep. For example:

  • Vitamin B-6, or pyridoxine, may cause vivid dreams and may improve your ability to remember dreams. A small study gave college students very large doses of vitamin B-6 over five days and found their dreams were more vivid, colorful, and bizarre than normal. You should be able to avoid this problem by taking vitamin B-6 in the morning.
  • Vitamin B-12 helps your body produce energy, and a few people have reported that taking it in the evening makes them too energetic to fall asleep easily. Again, you can solve this by taking vitamin B-12 in the morning. Vitamin B-12 deficiency has been linked in some research to poor sleep in people with certain medical conditions. This problem may occur because the vitamin is needed for your body to produce melatonin, a hormone that helps you sleep. There’s also some medical evidence that taking large doses of vitamin B-12 can lead to reductions in the amount of time you sleep. But there’s no medical evidence that taking it earlier or later in the day can disrupt your sleep. If you take vitamin B-12 at the same time as your other B vitamins, in the morning, you should be fine.

Conversely, it’s possible that niacin, also known as vitamin B-3, may help you fall asleep. Anecdotal evidence indicates that taking a high dose helps some people fall asleep more easily. However, you shouldn’t drink alcohol when also taking niacin, since alcohol can accentuate niacin’s effects. Since you’re more likely to enjoy an alcoholic beverage in the evening than in the morning, this may complicate your analysis.

Based on all of this, you may be better off taking B vitamins in the morning. But if B vitamins as a group don’t seem to bother your sleep and it’s more convenient for you to take them in the evening that should be fine, as well.

  • Vitamin C

Vitamin C helps your immune system function more effectively, and also plays an important role in helping protect your cells from the dangers of free radicals. It’s water-soluble, so you don’t need to take it with a meal. However, some people find vitamin C, especially in larger doses, can upset their stomachs and possibly even cause diarrhea. Taking this supplement with a meal can help, and taking a buffered type of vitamin C also can help if you find your digestive system is bothered by it.

Anecdotally, a few people have reported that larger doses of vitamin C have interfered with their sleep. There’s no real medical evidence for this, but if you’re concerned about it, you can take vitamin C in the morning and also cut back your dose to the recommended daily amount, which is 75 milligrams for adult women and 90 milligrams for adult men.

Vitamin C can help your body absorb iron better, so if your doctor has recommended you take extra iron, you should take your vitamin C at the same time, regardless of what time of day that occurs.

  • Vitamin D

Vitamin D, the “sunshine vitamin,” serves many roles in your body. It helps keep your immune system in good shape, it works in conjunction with calcium to build your bones, and your nerves use it to carry messages. Your body makes vitamin D when your skin is exposed to the sun. But because you risk getting skin cancer from excessive sun exposure, you may need to supplement vitamin D if your levels are low.

It is a fat-soluble vitamin, which means it is best taken with a meal that contains some fat. However, that meal can be breakfast, lunch, or dinner, since there’s no evidence that vitamin D absorption is better or worse at any particular time of day.

Anecdotally, some people report that vitamin D may interfere with sleep, especially when taken too late in the day. That effect may result because vitamin D may decrease your body’s supply of melatonin, the hormone that makes you sleepy. However, no studies have looked specifically at whether taking vitamin D in the afternoon or evening could affect sleep.

At least two studies have considered whether taking larger doses of vitamin D can interfere with sleep, regardless of when those doses were taken. One study found that women with multiple sclerosis taking high levels of vitamin D—4,370 IU, or upwards of seven times the recommended daily intake—had lower levels of melatonin in their blood. Women taking 800 IU per day didn’t see that effect, and the study didn’t evaluate sleep quality, so it’s difficult to draw full conclusions.

Another study found that older women who were trying to lose weight and who were taking 2,000 IU of vitamin D per day because they were deficient saw their sleep quality deteriorate. The study concluded that this level of vitamin D supplementation could result in poorer sleep quality among post-menopausal women who already were deficient in vitamin D.

It’s difficult to say whether you’re better off taking vitamin D in the morning or later in the day, although some people report anecdotally that they have better luck with a morning routine. Regardless, it’s possible that very large doses might interfere with sleep, no matter when they’re taken.

  • Vitamin E

Vitamin E protects your cells from damage, boosts your immune system, and helps to widen blood vessels and prevent blood clots. Deficiencies can cause nerve damage, vision problems, and a weakened immune system.

Since it’s a fat-soluble vitamin, you need to take vitamin E with a fat-containing meal. Beyond that advice, there’s no evidence that taking it at any particular time of day is better or worse for your health.

  • Vitamin K

Vitamin K helps your blood clot. It also assists in building strong bones, may protect you from cancer, and fights diabetes by improving your body’s sensitivity to the hormone insulin.

It’s another fat-soluble vitamin, so take vitamin K with a meal. However, there’s no research showing a “best” or “worst” time of day to take your vitamin K, so fit it in whenever you can do so.

  • Calcium

You’ve probably heard that calcium builds strong bones and that many people don’t consume enough of it. Adults and children 4 and older need between 1,000 and 1,300 milligrams of calcium a day, and many people (especially those who don’t drink much milk or eat calcium-supplemented foods) don’t get that much.

There are different types of calcium, and different recommendations for how to take them. Calcium citrate (a common form of calcium in supplement products) can be taken by itself or with a meal. Calcium carbonate (a less expensive supplement) needs the help of stomach acid to break it down, so it’s best taken with food.

Since you should divide up your dosage of calcium throughout the day for the best absorption (your body won’t absorb more than 500 milligrams at a time well), you may wind up taking calcium both in the morning and in the afternoon or evening, especially if your doctor has recommended you consume a larger dose of it daily.

Ideally, you shouldn’t take calcium at the same time as an iron-containing multivitamin or magnesium, since your body might not absorb it as well. However, some research indicates that calcium may help you fall asleep, and many supplement products combine calcium and magnesium into one (often very large) pill. You’ll need to decide (in consultation with your doctor) what’s best for you.

Finally, calcium supplements can interfere with certain medications, including antibiotics, medicines for osteoporosis, blood pressure medications, antacids, anti-seizure medications, and cholesterol medications. In some cases, taking calcium can mean your body absorbs more of the medication, while in other cases, your body may absorb less of the medication. Therefore, it’s critical to talk with your doctor about how your prescribed medications might interact with calcium (or any other supplement you take).

  • Magnesium

Magnesium, a mineral, works in your body to regulate nerve function, control blood pressure, and build bone (in conjunction with calcium). Most people get enough magnesium, but magnesium deficiency can cause nausea, loss of appetite, fatigue, and weakness.

Out of all the vitamins and minerals you can take, magnesium is the one that’s best taken at night. That’s because magnesium promotes sound, healthy sleep when it’s taken close to bedtime. In people who suffer from leg cramps at night, magnesium also may help to alleviate that problem.

Magnesium can be hard on your digestive system and may cause loose stools. In fact, the popular constipation remedy Milk of Magnesia contains 1,200 milligrams of magnesium hydroxide, which usually is enough to produce a bowel movement within six hours. If you find magnesium seems to be causing you to have loose stools, try cutting back on your dosage; a dose of 100 milligrams may be enough for you.

  • Multivitamins

Multivitamins combine what researchers consider to be the most important vitamins and minerals into one easy-to-take daily pill (or, in some cases, several daily pills). It’s common for multivitamins to include vitamin C, some or all B vitamins, vitamins A, D, E, and K, plus minerals such as zinc, selenium, and copper.

The use of multivitamins has dropped over the years as more people started to take individual supplements, such as vitamin D. However, nearly one-third of Americans still take a daily multivitamin.

There’s no “best” time to take your multivitamin, although many people take a multivitamin in the morning, especially if they have other morning medications to take. You definitely should take your multivitamin with food, though, since some of the vitamins in it most likely are fat-soluble. Some larger multivitamin supplements can cause stomach upset if taken on an empty stomach, as well.

It’s possible, although far from proven, that multivitamins may cause sleep disturbances. However, more research is needed to determine how multivitamins affect your sleep, if they do at all, and whether the time of day you take them can impact this. There just isn’t enough information to recommend avoiding multivitamins at night, so you can take them whenever you find it most convenient.



Vitamin and mineral supplements can’t help you if you don’t remember to take them. Therefore, the best time to take your vitamins is when you’re most likely to remember to take them. Many people make taking their vitamins part of their morning routine, and this should work fine, provided your breakfast contains some fat calories.

If you’re confused about what vitamins and minerals to take and when to take them, talk to your doctor. They can help you sort out which supplements you should be taking, and talk to you about the best time for you to take them. In addition, you should always let your doctor know if you take any over-the-counter vitamins, minerals, or other supplements, since they could interact with medications.



  • National Institutes of Health. Vitamin C fact sheet.
  • Bagur MJ et al. Influence of Diet in Multiple Sclerosis: A Systematic Review. Advances in Nutrition. 2017 May 15;8(3):463-472. DOI: 10.3945/an.116.014191.
  • Lichstein KL et al. Vitamins and Sleep: An Exploratory Study. Sleep Medicine. 2007 Dec;9(1):27-32. DOI: 10.1016/j.sleep.2006.12.009.
  • Kantor ED et al. Trends in Dietary Supplement Use Among US Adults From 1999-2012. JAMA. 2016;316(14):1464-1474. DOI: 10.1001/jama.2016.14403.


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