Vitamins

A complex organic substance required in the diet in small amounts, compared with other dietary components. The absence leads to a deficiency disease.

A type = fat soluble factor B type = heat labile factor

13

A, D, E, K B complex and C

Water soluble: • not stored extensively • needed regularly • generally not toxic in excess • most function as cofactors for enzyme-catalysed reactions Fat soluble: • stored • not easily absorbed • not excreted easily • may be toxic in excess (A&D)

Co-enzymes in metabolic pathways.

Whole grain, pork, poultry, fish, vegetables, dairy produce. Polished rice, sugar, fat and processed food.

• Biochemical role in glycolysis • Pyruvate to acetyl CoA • If deficient, there is accumulation of lactate Alcoholism

Primary - not taking enough in diet Secondary - taking enough but it is not used properly in body Iatrogenic - caused by medical examination or treatment

• May have adequate energy intake but as ‘empty calories’ from alcohol • Inadequate levels of vitamins and other nutrients • GI tract malfunctions are common • Cirrhotic liver affects storage, transport and metabolism of many vitamins • Storage and transport of fat soluble vitamins e.g. vitamin A, may be impaired

Functions as FAD and FMN in redox reactions. Taken mainly in milk

Function as NAD and NAPH in redox reactions. Source is in cereal.

Essential for amino acid metabolism and harm synthesis. Most common as a secondary deficiency, causes by antagonistic presence.

• Retinol containing foods • Full fat dairy produce, liver and kidney • Provitamin A containing foods

B12 - carrier of methyl groups in mammalian metabolism Folate - carrier of 1C units

Can carry CHO, CH=NH, CH, CH2, CH3. Responsible in making purines and pyrimidines.

B12 is only from animal tissues. It binds to glycoproteins secreted from gastric cells (the intrinsic factor). Needed for the absorption and transport of B12. Folate is mainly found in green vegetables and the liver. Absorbed in GI.

Folate becomes dihydrofolate then tetrehydroflate duding DHF reductase. This binds to methyl groups forming methyl tetrahydrofolate. B12 is therefore needed to get the methyl from tetrahydofolate. This means it can go back and carry more methyl groups.

B12 and folate needed for thymidylate synthesis and DNA. B12 dependant methionine synthesise only means of Me THF return into the folate pool. B12 deficiency traps THF in in the Me THF form producing functional THF deficiency. Haemopoietic cells dies in bone marrow without completing cell cycle.

B12 affects myelin synthesis Numb fingers Tingling hands Loss of position sense Unsteadiness, confusion, moodiness, depression

Component of the coenzyme A in the metabolism and transfer of carbon chains.

Normally sufficient quantities from intestinal bacterial synthesis. It is a prothetic group for carboxylations.

Source - citrus fruits, tomatoes, berries Antioxidant. Hydroxylation of proline and lysine in collagen formation. Needed to maintain the Fe2+ necessary for proline and lysine hydroxylase activity in the reduced, active state.

Oxalate kidney stones in susceptible individuals. Diarrhoea. Systemic conditioning (pregnant women on high doses will have infants with exceptionally high requirements)