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Digestion of Vitamins

Vitamins are an essential part of your dietary regimen to maintain bodily functions. Your body cannot make vitamins on its own, so they must be obtained from the foods you eat. The digestion and absorption of vitamins is a delicate balance of the right concentration, the health of your digestive tract and phytonutrients that help with absorption. When vitamins are absent from your diet, deficiencies can occur, which is the primary reason to ensure proper digestion of vitamins.

Classification of Vitamins

Two types of vitamins are essential for proper bodily function: fat-soluble and water-soluble vitamins. Fat-soluble vitamins include vitamins A, D, E and K, and the digestion of these vitamins is enhanced in the presence of fat. Fat-soluble vitamins are stored within your liver, intestines and fatty tissues of the body. B-complex vitamins and vitamin C are water-soluble. These vitamins are easily transported in your blood because it is made up primarily of water. Water-soluble vitamins have to be obtained through the diet daily because excess levels are excreted through your urine and feces. Unlike water-soluble vitamins, fat-soluble vitamins can become toxic at high doses because they are stored in your body.

Digestion of Vitamins

What Is the General Function of Vitamins?

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The availability of vitamins is dependent upon the food eaten, which releases the vitamins in the intestines. Fat-soluble vitamins require fat or lipid micelles as a carrier for transportation in the blood to travel to the liver and other fatty tissues. Water-soluble vitamins are digested and transported into the blood through active-transport channels in the intestine, meaning the concentration of the vitamin allows for channels to open and the vitamin to cross the intestines to a specific protein in the blood. Vitamin B-12 needs a specific transport protein called the intrinsic factor for absorption. The intrinsic factor is a protein produced by the stomach to combine with vitamin B-12 when stomach acid comes in contact with food for digestion, according to Colorado State University. When vitamin B-12 and intrinsic factor reach the small intestines, the pH of the digested food becomes higher, allowing both components to combine and B-12 to become absorbed into your bloodstream.


The small intestine serves as the primary site of vitamin digestion and absorption. Vitamins perform various functions in the body. Vitamin C is incorporated into collagen, a protein that serves to provide structure for your bones and skin. Vitamin D acts to enhance calcium absorption from your small intestines and incorporate calcium into your bones. Vitamin K maintains proper blood clotting proteins and increases calcium deposition in your bones in addition to vitamin D. B-complex vitamins aid in the digestion and use of carbohydrates, proteins and fat for energy.


What Do Multivitamins Do for the Body?

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Vitamins are vital for life. Supplements can provide necessary vitamins that may be deficient or insufficient in your diet. Vitamin supplements may not have necessary co-factors to enhance absorption, which is why it is recommended you take them with food. Certain segments of the population have an increased risk for deficiency with certain vitamins. The elderly or those taking medications to reduce acid production of the stomach may need additional B-12 to prevent anemia. Growing children and teenagers who avoid certain foods because of taste preferences may need additional support in obtaining necessary amounts of certain vitamins. Speak with your health care provider before starting a new dietary supplement, especially if you suspect a nutritional deficiency.