Vitamin protein intake

The typical U.S. daily diet contains 1.1—3.6 mg of vitamin B, most coming from meats and vegetables. Poor diets may provide less than half of these amounts and less than the RDA. Some populations require higher amounts persons with high protein intakes, pregnant and lactating women, users of oral contraceptives, alcohoHcs, users of dmgs which interfere with vitamin B function, and those afflicted with some diseases. Several reviews have examined the relationship of vitamin B and specific diseases in more detail (4,23). 

Vitamin Ba (pyridoxine, pyridoxal, pyridoxamine) like nicotinic acid is a pyridine derivative. Its phosphorylated form is the coenzyme in enzymes that decarboxylate amino acids, e.g., tyrosine, arginine, glycine, glutamic acid, and dihydroxyphenylalanine. Vitamin B participates as coenzyme in various transaminations. It also functions in the conversion of tryptophan to nicotinic acid and amide. It is generally concerned with protein metabolism, e.g., the vitamin B8 requirement is increased in rats during increased protein intake. Vitamin B6 is also involved in the formation of unsaturated fatty acids. 

Homocysteine, which initiates proatherogenic changes in endothelium, can be reduced in many patients by restriction of total protein intake to the amount required for amino acid replacement. Supplementation with folic acid plus other vitamins is indicated in severe homocyteinemia. 

Since vitamin B6 is essential for amino acid (and hence protein) metabolism, its RDA is quoted in terms of protein intake (0.016 mg per g protein per day, equivalent to about 2.0 and 1.6 mg day-1 for men and women,... 

Supplementation with the antioxidant vitamins ascorbic acid (250 mg) and mixed natural tocopherols (50 IU on alternate days) may be beneficial. Higher doses may vitiate the impact of lipid lowering therapy. Other naturally occurring antioxidants such as resveratrol, 3-catechin, selenium, and various carotenoids found in a variety of fruits and vegetables may provide additional antioxidant defense. Homocysteine, which initiates proatherogenic changes in endothelium, can be reduced in many patients by restriction of total protein intake to the amount required for amino acid replacement. Daily supplementation with up to 2 mg of folic acid plus other B vitamins is also recommended. 

He was provided with a diet restricted in protein but was found to limit his own protein intake to 1.0 to 1.2 g/kg. Treatment with large doses of vitamin B12 for a period of 4 months made no difference to the concentration of methylmalonic acid excreted in his urine. He required frequent hospitalization for anorexia, vomiting, and dehydration. At 18 months of age he developed renal failure, and at 3 years he became oliguric. His physical development appeared normal for the first 12 months and then it deteriorated. He started to walk at 31 years, but at this time he also had hepatomegaly and persistent vomiting. On the basis of a developmental screening test he was found to be 12 to 18 months behind in all areas tested. 

Kelsay J, Miller LT, and Linkswiler H (1968b) Effect of protein intake on the excretion of quinolinic acid and niacin metabolites by men during vitamin Bg depletion. Journal of Nutrition 94,27-31. 

DEFICIENCY Vitamin A deficiency results in night blindness and xerophthalmia (dry cornea and conjunctiva, sometimes with ulceration of the cornea). Nonocular changes may also occur dry skin and mucous membranes. Deficiency may result from poor dietary intake, or poor absorption, as from bowel disease, or a defect in bile flow that causes fet malabsorption. Poor protein intake may result in a reduced level of the transport protein that carries vitamin A in the blood stream. 

Human requirements for vitamin parallel protein metaboHsm, with increased intake of protein requiring higher intake of the vitamin. As Htde as 0.010—0.015 mg of vitamin per gram of protein prevents deficiency signs with adequate protein intake. Slightly higher intake maintains acceptable... 

Pyridoxine (vitamin Be) requirements vary with protein intake the daily Average Requirement is 13 micrograms/ g protein intake and the Population Reference Intake is 15 micrograms/g protein intake. In adults this translates into a daily Average Requirement of 1.3 mg/day for men and 1.0 mg/day for women, and a Population Reference Intake of 1.5 mg/day for men and 1.1 mg/day for women. 

Young children seem to be particularly at risk of vitamin A toxicity. Symptoms of chronic intoxication are seen with intakes of 800-16 000 micrograms/kg RE (2500-50 000 lU/kg) (21). Children with restricted protein intake may have reduced tolerance to vitamin A. 

Manganese Nausea, vomiting, dermatitis, hair color changes, hypocholesterolemia, growth retardation, defective carbohydrate and protein metabolism Parkinsonian-like symptoms, hyper irritability, hallucinations, libido disturbances, ataxia Increased decreased biliary excretion high iron or vitamin C intake... 

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