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.
Some vitamins that should not be taken together, or have dosage limitations, include vitamin C with vitamin B-12, vitamin A supplement with vitamin A-rich foods, folic acid (vitamin B9) and vitamin B12, and vitamin E with vitamin K.
It may be best to take fat-soluble vitamins apart from one another, as evidence (mainly from animal and cell studies) suggests that moderate to large doses of fat-soluble vitamins reduce absorption of other fat-soluble vitamins - by about 10 to 50% - due to competition.
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.
Combining multiple supplements or taking higher-than-recommended doses can increase the risk that they can cause harm, said Kitchin. "You really can't get toxic doses of nutrients through food, but you can absolutely get toxic doses through supplements," Kitchin said.
Melatonin and other sedating herbs
You can easily overdo herbs or supplements with sedative properties. These include melatonin, valerian, ashwagandha, kava, and St. Johns's Wort: “When taken together, they can cause too much sleepiness,” Dr. Cooperman says.
Yes! You can and should take magnesium and vitamin D together. In fact, the bioavailability of vitamin D largely relies on magnesium. Also, many nutrients wouldn't work efficiently without magnesium, further highlighting the importance of this mineral!
Vitamins D, E and K
“Studies have shown that a person's absorption of Vitamin K may be reduced when other fat-soluble vitamins such as Vitamin E and Vitamin D are taken together,” says Dr. Chris Airey, M.D. “It's advised that you take these vitamins at least 2 hours apart to maximize your absorption.”
It's safe to consume vitamin D and the B complex together as a supplement or through food sources. However, if you're on medications or have a medical condition, consult your doctor about any drug interactions before taking supplements.
Vitamin C (ascorbic acid) supplements.
Taking vitamin B-12 with vitamin C might reduce the available amount of vitamin B-12 in your body. To avoid this interaction, take vitamin C two or more hours after taking a vitamin B-12 supplement.
Dwyer says vitamin D, calcium, and folic acid are three nutrients you may get too much of, especially through supplements. Adults who regularly far exceed the 4,000 international units (IUs) daily safe upper limit for vitamin D might may end up with serious heart problems.
Mayo Clinic suggests aiming to leave at least one to two hours between vitamins. “I usually tell people to take them at a separate meal,” says Brissette. Also keep in mind that your body can only absorb 600 mg of calcium at a time—so if you're taking more, have one dose in the morning and one in the evening.
Together, zinc and vitamin D in adequate concentrations help maintain a healthy musculoskeletal system and beyond; however, deficiency in either of these nutrients can result in various disorders affecting almost all body systems. This brief article will focus on the role of zinc in vitamin D functions.
Our only hard recommendation: Avoid supplementing with vitamin D at night. There's evidence that vitamin D can suppress melatonin—which is bad news for your sleep quality.
Vitamin C works best in combination with vitamin E, ferulic Acid, vitamin B, and hyaluronic acid.
Vitamin C can be destroyed by heat and light. High-heat cooking temperatures or prolonged cook times can break down the vitamin. Because it is water-soluble, the vitamin can also seep into cooking liquid and be lost if the liquids are not eaten.
Pair: Iron + Vitamin C
Taking iron and vitamin C together helps boost iron absorption, which can be really helpful for vegetarians and vegans especially who might be lacking in this rock star nutrient.
Nassar says that taking a magnesium supplement every day likely isn't unsafe for most people. Just be sure you're not taking too much magnesium. The maximum dietary allowance for most adults is around 400 mg or less.
Do not take zinc supplements and copper, iron, or phosphorus supplements at the same time. It is best to space doses of these products 2 hours apart, to get the full benefit from each dietary supplement.
Interactions between your drugs. No interactions were found between Vitamin B12 and Vitamin D3.
Extra amounts of water-soluble vitamins are typically excreted. The fat-soluble vitamins A and D are the most likely to cause toxicity symptoms if you consume them in high amounts.