Large doses of minerals can compete with each other to be absorbed. 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.
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.
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.
Magnesium and calcium/multivitamin
But if you do take magnesium, Erin Stokes, ND, recommends not taking it at the same time as your multivitamin, as it may interfere with the absorption of smaller minerals found in the multivitamin, like iron and zinc.
Vitamin C + Niacinamide
However, when you combine niacinamide with Vitamin C, they'll cancel each other out chemically, making both formulas ineffective on your skin. Niacinamide takes out all the good properties of Vitamin C and makes it into a substance that can cause redness and trigger breakouts.
B vitamins work together (such as in a B complex supplement that contains B12, folate, B6, etc.), so they can/should be taken together. Vitamin C and iron (C helps the body absorb more iron, from both foods and supplements) Vitamin K and calcium (both support skeletal and heart health)
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!
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.
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.
Consumption of vitamin D supplements without enough magnesium can lead to problems such as vascular calcification. Calcification happens when calcium builds up in body tissue, blood vessels, or organs and vascular calcification refers to build-up in the arteries and veins.
Because vitamin D is fat soluble, its absorption depends on the gut's ability to absorb dietary fat [4]. Fat malabsorption is associated with medical conditions that include some forms of liver disease, cystic fibrosis, celiac disease, Crohn's disease, and ulcerative colitis [1,63].
Magnesium supplements should be taken with meals. Taking magnesium supplements on an empty stomach may cause diarrhea.
Interactions between your drugs. No interactions were found between Vitamin B12 and Vitamin D3.
Vitamin C works best in combination with vitamin E, ferulic Acid, vitamin B, and hyaluronic acid.
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.
Vitamin C is generally considered safe because your body gets rid of what it does not use. But at high doses (more than 2,000 mg daily) it can cause diarrhea, gas, or stomach upset. If you experience these side effects, lower the dose of vitamin C.
Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs) interacts with MAGNESIUM. Magnesium might slow blood clotting. Taking magnesium along with medications that also slow clotting might increase the chances of bruising and bleeding.
People with diabetes, intestinal disease, heart disease or kidney disease should not take magnesium before speaking with their health care provider. Overdose. Signs of a magnesium overdose can include nausea, diarrhea, low blood pressure, muscle weakness, and fatigue. At very high doses, magnesium can be fatal.
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.
Try taking it alongside breakfast or with a bedtime snack — as long as it doesn't interfere with your sleep. The key is to find what works for you and stick with it to ensure you're meeting your vitamin D needs. Taking vitamin D with a meal can increase its absorption, but studies on specific timing are limited.