Vitamins- Metabolic functions and food sources

Lesson 29 : The Role of Vitamins & Minerals in Metabolism

Vitamins- Metabolic functions and food sources


Metabolic functions

Significant food sources

B1 (thiamin)

Supports energy metabolism and nerve function
Functions as the thiamine pyrophosphate, a coenzyme for several enzymes involved in decarboxylation reactions. Required, for example, in the oxidation of glucose due to its role in decarboxylation of pyruvate.

spinach, green peas, tomato juice, watermelon, sunflower seeds, lean ham, lean pork chops, soy milk

B2 (riboflavin)

Supports energy metabolism, normal vision and skin health
Precursor to the coenzymes flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN), which serve as hydrogen carriers in a number of important oxidation-reduction (respiration) reactions within mitochondria.

spinach, broccoli, mushrooms, eggs, milk, liver, oysters, clams

B3 (niacin)

Supports energy metabolism, skin health, nervous system and digestive system
Precursor to the coenzymes nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADPH), which serve as hydrogen carriers in such important processes as glycolysis, Kreb's cycle and oxidative phosphorylation.

spinach, potatoes, tomato juice, lean ground beef, chicken breast, tuna (canned in water), liver, shrimp


Energy metabolism, fat synthesis, amino acid metabolism, glycogen synthesis
Functions as a coenzyme for several enzymes that catalyze carboxylation, decarboxylation and deamination reactions. One example is pyruvate carboxylase, an essential enzyme of Kreb's cycle

widespread in foods

Pantothenic Acid

Supports energy metabolism
The precursor to coenzyme A, which is an enzyme critical to the oxidation and/or synthesis of carbohydrates and fatty acids.

widespread in foods

B6 (pyridoxine)

Amino acid and fatty acid metabolism, red blood cell production
The precursor to pyridoxal phosphate, a coenzyme for several important reactions involving protein metabolism, including the transamination reactions necessary for synthesis of amino acids.

bananas, watermelon, tomato juice, broccoli, spinach, acorn squash, potatoes, white rice, chicken breast


Supports DNA synthesis and new cell formation
Serves as a coenzyme in the synthesis of several amino acids, as well as purines and thymine, and therefore DNA. Deficiency is typically manifest as growth failure and anemia.

tomato juice, green beans, broccoli, spinach, asparagus, okra, black-eyed peas, lentils, navy, pinto and garbanzo beans


Used in new cell synthesis, helps break down fatty acids and amino acids, supports nerve cell maintenance
A cobalt-containing coenzyme involved in numerous metabolic pathways. Deficiency usually results from failure to absorb the molecule due to inadequate quantities of intrinsic factor, and is typically manifest as a defect in red blood cell formation (pernicious anemia).

meats, poultry, fish, shellfish, milk, eggs

C (ascorbic acid)

Collagen synthesis, amino acid metabolism, helps iron absorption, immunity, antioxidant
A major function is synthesis of hydroxyproline, an important component of collagen and, thereby, all connective tissues. Essential for growth of cartilage, bone and teeth, and for wound healing. Deficiency results in the disease scurvy.

Most animals can synthesize ascorbic acid; those that cannot include primates (including humans), guinea pigs. Food sources are spinach, broccoli, red bell peppers, snow peas, tomato juice, kiwi, mango, orange, grapefruit juice, strawberries

A (retinol)

Supports vision, skin, bone and tooth growth, immunity and reproduction
Necessary for a broad range of bodily function, including production of vision pigments, resistance to infectious agents and maintenance of health in many epithelial cells. Disease results from both deficiency and excess.

mango, broccoli, butternut squash, carrots, tomato juice, sweet potatoes, pumpkin, beef liver


Promotes bone mineralization
A steroid hormone. Major effect is to facilitate absorption of calcium from the intestine, and thereby assist in maintaining calcium homeostasis. Receptors are present in most cells and it likely has many additional effects

self-synthesis via sunlight, fortified milk, egg yolk, liver, fatty fish


Antioxidant, regulation of oxidation reactions, supports cell membrane stabilization
A family of molecules that function as antioxidants, particularly to prevent oxidation of unsaturated fatty acids and maintain the integrity of cell membranes. Deficiency can lead to reproductive function, leading to the nickname of "antisterility vitamin".

polyunsaturated plant oils (soybean, corn and canola oils), wheat germ, sunflower seeds, tofu, avocado, sweet potatoes, shrimp, cod


Synthesis of blood-clotting proteins, regulates blood calcium
Necessary for formation of several blood-clotting factors in the liver, and deficiency leads to bleeding disorders.

Brussels sprouts, leafy green vegetables, spinach, broccoli, cabbage, liver

Last modified: Tuesday, 24 January 2012, 10:40 AM