Nutritional status of vitamin

Sauberlich HE, Canham JE, Baker EM, Raica N Jr, and Herman YF (1972) Biochemical assessment of the nutritional status of vitamin B 6 in the human. American Journal of Clinical Nutrition 25, 629-42. 

Many factors affect folate metabolism, including dietary folate level, nutritional status of vitamins B6, B12, and riboflavin, zinc status, alcoholism, and physical states such as pregnancy and lactation. In many cases, the effects of these factors are seen in altered excretion rates of intact folates and metabolites, but the effects on tissue levels of the various folates and transfer rates between tissues are not well understood. Preliminary human and animal kinetic models are being devek ed in our laboratory based on studies conducted under controlled dietary conditions. These models will provide a base from which to study the effects of altered folate nutriture as well as the influence of other factors such as pregnancy and aging on folate metabolism. 

Deficiency syndromes of Zn, Cu, Cr, Se and Mo have occurred in patients on total parenteral nutrition (TPN). There is still much research to be done in assessing the nutritional status of many elements and understanding their metabolism, so that normal dietary intake may be supplemented for health benefits. Table 2 is a summary of the amounts required, the functions and the nutritional (usually dietary) imbalances in humans, where known, of the essential trace elements.31-33 (Note that this summary does not attempt to include imbalances related to environmental toxicology and occupational hazards.) Several trace elements have important functions in the immune system. Some are associated with nucleic acid. Others have structural roles, such as Si in cartilage, F and Zn in bone. They may be parts of vitamins, such as Co in vitamin B12, or hormones, such as iodine in thyroid hormones, Zn and Cr have a role in the synthesis and action of insulin.31-33... 

Increasing evidence indicates that diet/nutrition plays an important role in modulating the action and/or metabolism of a number of chemicals, drugs and environmental pollutants. Nutrients are essential for all fundamental cellular processes. The nutritional status of the affected subject may, therefore, influence cellular susceptibility to the effect of xenobiotics, including those from cigarette smoke. While the precise role of vitamin E in cellular metabolism is not yet clear, the vitamin may protect essential cellular components from the adverse effects of xenobiotics either via a free radical scavenging mechanism or as a component of the cell membrane (10-11). Administration of vitamin E has been shown to lessen the toxicity of a variety of compounds (12-16). 

Table I summarizes the status of vitamin E and Se in various tissues obtained from rats subjected to altered vitamin E and/or Se nutrition. It is evident from the Table that the animals fed on vitamini E and/or Se-deficient diets showed marked decrease in tissue levels of vitamin E and/or Se respectively. This indicates that the diets employed in these experiments induced desirable deficiency states of vitamin and/or Se. In general, vitamin E levels were affected more in microsomes than in cytosols under vitamin E-deficiency states.

Whole blood ascorbic acid values may be a less sensitive indicator of vitamin C nutriture than serum or plasma levels of the vitamin because the vitamin C content in erythrocytes never falls to the low levels found in serum or plasma (89,90). Also there are no well-established classifications available relating blood vitamin C values to the nutritional status of this vitamin in a population (88). 

Considerable uncertainty and controversy exists concerning the folate requirement for humans. Hie review of data concerning the human folate requirement by the Food and Nutrition Board (1989) suggests that the daily maintenance requirement is 100-200 fig of avaUable folic acid equivalents. The 1989 RDAs were reduced to 200 and 180 fig for adult men and women, respectively, from the previous RDA of 400 on the basis of such evidence (Food and Nutrition Board, 1989). Similarly, the Canadian RDA for folate was set at 3 /ig/kg body wt or 210 fig for a 70-kg individual. These lower RDAs may be inadequate for certain population groups, however (Sauberlich, 1990 Bailey, 1992 McPartlin etai, 1 3). It is currently difficult or impossible to predict the quantitative effect on folate nutritional status of factors such as (a) changes in folate intake, (b) differences in folate bioavailability, (c) effects of pregnancy and lactation on folate requirements, and (d) pharmaceuticals with antifolate properties. In addition, the development of mathematical models would improve our ability to evaluate methods of nutritional status assessment for this vitamin. 

Chang, S., and Kirksey, A. (1990). Pyridoxine supplementation of lactating mothers Relation to maternal nutrition status and vitamin B-6 concentrations in milk. Am. J. Clin. Nutr. 

The contention that ascorbate is involved in resistance to neoplasia gains support from the many studies demonstrating that cancer patients have abnormally low ascorbate reserves. When this was first demonstrated many years ago, there was a tendency to assume that such a finding merely reflected the poor general nutritional status of advanced cancer patients. Such a view is no longer tenable, and it is now generally agreed that low levels in cancer indicate an increased utilization and requirement for the vitamin. 

Related analyses in the meat and meat products area are the analysis of curing brines and of special meat fractions such as mechanically recovered meat (MRM). Completing the list of analyses on meat and meat products are the mineral and vitamin assays used to characterize the nutritional status of these foods. 

Vitamin K1 (phylloquinone) exists naturally only in the trans-form. Trans- and cii -isomers are formed during UV light exposure or synthetic production of vitamin Kl. This cw-isomer is considered to have low bioactivity [84]. Therefore, inactive cii-vitamin Kl is necessary to measure individually to evaluate the true nutritional status of fortified foods. The developed method proved to be rapid and sensitive, which allows cis- and trans-vixasam Kl extracted from milk-based, rice-based, and soy-based infant formula to be simultaneously determined by UPLC-MS/MS [83]. 

The results coincide with the general consensus that 4-PA is the major excretory metabolite of vitamin Bg and that its content in urine is a direct measure of the nutritional state of vitamin Bg in the human body (Leklem 1990). Interestingly, the PL and 4-PA contents showed a strong correlation with a correlation coefficient of 0.98 (Yagi et al. 2010b), suggesting that the PL content in urine also reflects the vitamin Bg status in the human body. In contrast, no correlation (correlation coefficient of 0.07) was found between the PM and 4-PA contents. Analysis of individual vitamin Bg forms in urine from various people consuming usual foods should provide us with novel aspects of vitamin Bg metabolism. 

Due to the function of GSH peroxidase in metabolizing lipid hydroperoxides, the nutritional status of selenium may determine cellular susceptibility to the effects of peroxidized Upid administered. By feeding 7% oxidized stripped corn oil (peroxide value lOOOmequiv./kg) in a diet adequate in selenium and vitamin E to weanling rats for 14 weeks, Vilas et al. (1976) have shown an increase in specific activity of GSH peroxidase... 

K Shibata. The metabolism of niacin in each organ and the biological method for assessing the nutritional status of niacin in the rats. Vitamins (Japan) 61 39-56, 1987. 

Deficiency Diseases. Not only did cereals make an important contribution to improving the general status of humankind, but they also were important dietary components of some groups of people who showed certain nutritional deficiencies. This observation led to the discovery of some of the vitamins. These deficiency diseases have been most prominently associated with use of rice, com, and wheat. 

However, results obtained by Koo et al. (1991) indicate that low to moderate lead exposure (average lifetime PbB level range of 4.9-23.6 pg/dL, geometric mean of 9.8 pg/dL, n=105) in young children with adequate nutritional status, particularly with respect to calcium, phosphorus, and vitamin D, has no effect on vitamin D metabolism, calcium and phosphorus homeostasis, or bone mineral content. The authors attribute the difference in results from those other studies to the fact that the children in their study had lower PbB levels (only 5 children had PbB levels >60 pg/dL and all 105 children had average lifetime PbB levels <45 pg/dL at the time of assessment) and had adequate dietary intakes of calcium, phosphorus, and vitamin D. They concluded that the effects of lead on vitamin D metabolism observed in previous studies may, therefore, only be apparent in children with chronic nutritional deficiency and chronically elevated PbB levels. Similar conclusions were reached by IPCS (1995) after review of the epidemiological data. 

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