“The best time to take a multivitamin is with food so any fat can help with absorption. You can also drink a water-based beverage to wash it all down,” notes Dr. Perez-Gallardo. “But the drawback is that your body won't absorb the water-soluble vitamins as well as fat-soluble ones.”
“Digestion slows down during sleep, so taking your nutrient supplement late at night would not be associated with an efficient absorption.” Neil Levin, a clinical nutritionist at NOW Foods, agrees that morning is best for multivitamins and any B vitamins.
To maximize nutrient absorption, consume your fat-soluble vitamins (A, D, E, and K) with fats or oils that can help with absorption. For example, when taking your multivitamin in the morning, consume it with a nut butter, such as almond butter, cashew butter or peanut butter.
You can—but it's probably not a good idea. For some supplements, optimal absorption can depend on the time of day taken. Not only that—taking certain vitamins, minerals, or other supplements together can also reduce absorption and may result in adverse interactions, which can be harmful to your health.
Combining supplements will not normally interfere with the way they work and in some cases may be beneficial, for example vitamin C helps iron absorption.
The short and simple answer is: Yes! Vitamins C and D are commonly found together in multivitamins. They have complementary effects, which means that taking them together can better support your health. They're particularly beneficial to the immune system.
With a meal: Vitamin D is a fat-soluble vitamin. This means it does not dissolve in water. Your body absorbs Vitamin D better when it is consumed with healthy fats, such as avocados, nuts, eggs, and seeds. Taking your supplement with breakfast or lunch is recommended, or you can even take it with an afternoon snack.
We recommend taking it with a source of quality fat in the morning or when you break your fast. Avoid taking vitamin D in the evening (we'll talk about why below). Since vitamin D is a fat-soluble vitamin—meaning it doesn't dissolve in water—your body can most easily absorb it when you take it with food.
Magnesium assists in the activation of vitamin D, which helps regulate calcium and phosphate homeostasis to influence the growth and maintenance of bones. All of the enzymes that metabolize vitamin D seem to require magnesium, which acts as a cofactor in the enzymatic reactions in the liver and kidneys.
My sister-in-law said that the best way to test your vitamins is to place them in a glass of water. If they haven't dissolved in 50 minutes, it's likely you aren't absorbing any of the goodness that's inside that capsule or tablet.”
Don't use calcium, zinc, or magnesium supplements at the same time. Also, these three minerals are easier on your tummy when you take them with food, so if your doctor recommends them, have them at different meals or snacks.
“The best time to take a multivitamin is with food so any fat can help with absorption. You can also drink a water-based beverage to wash it all down,” notes Dr. Perez-Gallardo. “But the drawback is that your body won't absorb the water-soluble vitamins as well as fat-soluble ones.”
Try to avoid taking your vitamins with coffee or tea
So, wait an hour after your morning brew to take supplements. Caffeine-free herbal tea, on the other hand, contains fewer tannins than regular tea. This beverage may actually increase the absorption of certain minerals such as iron.
The time of day that you take a vitamin doesn't affect how well your body will absorb its properties. The main thing to consider is whether you're taking the vitamin with food or not. Since fat-soluble vitamins are better absorbed with food, you might want to plan to take such vitamins close to meal or snack times.
Therefore, conditions that affect the gut and digestion, like celiac disease, chronic pancreatitis, Crohn's disease, and cystic fibrosis, can reduce vitamin D absorption.
Is there a bad time to take vitamin D? Since vitamin D is fat soluble, it's best not to take it on an empty stomach. For maximum absorption, take it with a substantial meal, and preferably one that includes fat-containing foods like nuts, seeds, and eggs. (Or avocado toast at breakfast, for example!)
There's no set time of day that's best to take vitamin D supplements. Some people say taking vitamin D supplements at night is an insomnia risk. There's no research to confirm this, but you might want to take your supplement earlier in the day if you think it's screwing with your sleep.
Can you take vitamin D and magnesium together? Yes. In fact, it's probably best to take both together. Because so many people have low magnesium levels, vitamin D supplements on their own aren't very helpful for a large portion of the population.
If you are supplementing with vitamin D3, it's imperative you have enough magnesium to activate it. Why is this so important? Vitamin D3 cannot be utilized without sufficient magnesium; it simply remains stored in the body until it has enough magnesium to be activated.
Take vitamin D by mouth as directed. Vitamin D is best absorbed when taken after a meal but may be taken with or without food. Alfacalcidol is usually taken with food. Follow all directions on the product package.
Although the functions of vitamin C and magnesium may not overlap like other nutrients, there's no harm in taking them simultaneously. With no known interactions, vitamin C and magnesium can safely be supplemented together.