Which vitamins should not be taken together?

Updated July 19, 2017

Sometimes vitamins work well together in supplying nutrition and function to important areas of the body. Most vitamins function well together if they come from natural sources such as fruits, vegetables, sources of protein and grains. There are times when supplemental vitamins and even some natural sources contraindicate each other and should not be consumed with one another.

B Vitamins

B vitamins are interdependent of one another. They work best that way. When someone is lacking one B vitamin, another B vitamin deficiency is sure to follow. Sometimes when there is too much of one B vitamin, the body suffers for lack of equilibrium. If there is too much vitamin B1, it can bring insulin production into disorder and affect the thyroid adversely.


Niacin helps keep the skin clear, the brain alert and the digestive system calm and working. A deficiency in this vitamin will facilitate a skin breakout, unclear thinking and disrupted digestion and elimination. Niacin should not be taken by diabetics, people with glaucoma or those with ulcers until they talk with a doctor about it.

B-6 and Folic Acid Overdose

Vitamin B-6 should not exceed the recommended amount and override other B vitamins or it can damage the liver or nerves. Folic acid always needs to be taken with Vitamin B-12 to work effectively and not mimic B-12 deficiency. Too much folic acid can cause indigestion, flatulence and possible seizures.

Vitamin E and Vitamin K

Vitamin E is a vitamin that enables the blood to thin out. Vitamin K is a vitamin that enables the blood to clot. There are probably some foods that contain them both, offering a smoothing out of the blood. If you want to thin the blood due to excessive blood clots, you should not take those two vitamins together. If you want a better clotting factor, the same reasoning should be applied.

Magnesium and Calcium

Magnesium and calcium are both involved in the building of bone in the body. Calcium forms the outside, and magnesium is involved in the bone marrow. Sometimes magnesium and calcium contend to be absorbed by the same site in the body. Supplements should not be taken together if it interferes with the healing process.

Magnesium Glycinate and Magnesium Oxide

Magnesium glycinate and magnesium oxide are both forms of the same element. Magnesium glycinate is the form that is usually administered under the magnesium name. Even though the forms are related, they perform different functions for the body. They would cancel each other out or disrupt healing of the body if they were taken together.

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About the Author

During 17 years, Janin Santa won a scholarship for writing a science fiction short story and illustrated and published her own children's book, "Different Animals." She has CMA training, CNA training and graphic arts skills. She is working on a second children's book, "Dancing Pictures."