While you think all vitamins are good, some combinations can produce unexpected results. Part of the reason lies in the fact that you are taking large quantities simultaneously. Some foods may contain the same nutrients, but probably not in the same concentrations as found in vitamins. In addition, the chemical nature of some vitamins may also play a role. Some vitamins such as vitamin A are stored in the body, a factor that can lead to toxic levels over time. The possibility of harmful reactions exists with any drug, regardless of the health benefits it provides. Always consult with your doctor before taking any dietary supplements.
Vitamin B12 and Folic Acid
Vitamin B12 and folic acid are two of the eight B-complex vitamins. Both support energy production in the body. Vitamin B12 is essential for healthy red blood cell formation. Folic acid, sometimes referred to as vitamin B9, is important for amino acid metabolism. Amino acids are the building blocks for proteins. If you take a supplement high in either of these vitamins, you may hide the symptoms of a deficiency in the other, explains WholeHealthMD.com. Either scenario can lead to serious health consequences, such as anemia.
Pantothenic Acid and Biotin
Pantothenic acid and biotin are both B-complex vitamins as well. Your body requires pantothenic acid, vitamin B5, for the synthesis of fatty acids. Biotin, sometimes referred to as vitamin B7, plays a role in metabolic reactions in the body. If you take large quantities of pantothenic acid, it can cause deficiencies in the body's uptake of biotin. The two nutrients are similar from a chemical perspective, which creates this scenario. Deficiencies in biotin can cause hair loss and neurological symptoms such as depression and hallucinations.
Vitamin A and Vitamin K
Both vitamins A and K are fat-soluble chemicals that are stored in the body. Vitamin K ensures healthy blood clotting. Vitamin A provides beneficial effects on healthy vision and immune system function. Because your body stores these vitamins, the risk exists for harmful effects due to large quantities in the body. Vitamin A may interfere with the role that vitamin K plays as well. This can increase your risk for bleeding.
Vitamin E and Vitamin K
Vitamin E assists the body with blood clotting control. If you are vitamin K-deficient and take high quantities of vitamin E, you may increase your risk of dangerous hemorrhaging. A 2004 study by the Jean Mayer U.S. Department of Agriculture human nutrition research center on aging found that high doses of vitamin E increase the risk of hemorrhaging because of their negative effects on vitamin K, including impairing blood clotting by decreasing levels of a protein required by vitamin K. These findings show the complex chemical nature of the human body.