Dietary Allowance For Vitamin Research Articles

Vitamin D supplementation

To summarize recommendations from the 2011 US Institute of Medicine report (on vitamin D) and the new guideline from the US Endocrine Society with emphasis on treating and preventing vitamin D deficiency, including patients with inflammatory bowel disease and prior gastric bypass. The US Institute of Medicine Recommended Dietary Allowance of vitamin D is 400 IU per day for children younger than 1 year of age, 600 IU per day for children at least 1 year of age and adults up to 70 years, and 800 IU per day for older adults. The US Institute of Medicine concluded that serum 25-hydroxyvitamin D [25(OH)D] of 20 ng/ml or more will cover the requirements of 97.5% of the population. The US Endocrine Society's Clinical Practice Guideline suggested that 400-1000 IU per day may be needed for children aged less than 1 year, 600-1000 IU per day for children aged 1 year or more, and 1500-2000 IU per day for adults aged 19 years or more to maintain 25(OH)D above the optimal level of 30 ng/ml. Patients with inflammatory bowel disease even in a quiescent state and those with gastric bypass malabsorb vitamin D and need more vitamin D to sustain their vitamin D status. Difference in the recommendations from the US Institute of Medicine and the US Endocrine Society's Practice Guideline reflects different goals and views on current evidence. Significant gaps remain in the literature, and studies of vitamin D treatment assessing changes in outcomes at different 25(OH)D levels are needed.

Vitamin D in the light of current knowledge

Vitamin D, i.e., 1.25(OH)2D, is an essential factor, not only of homeostasis of calcium and phosphorus, but also of cell proliferation, differentiation and apoptosis, immune and hormonal regulation, as well as other body processes.Thus, its optimal presence in the body is of exceptional significance for health, both of children, as well as adults and elderly persons. Today, it is known that the lack of vitamin D, besides having negative effects on the skeleton and teeth, also contributes to the development of various malignancies, primarily of the large bowel, prostate and breasts, as well as of autoimmune and allergic diseases, diabetes mellitus type II, arterial hypertension and others. Considered from the biological aspect, physiological requirements in vitamin D are achieved by cutaneous synthesis from 7-dehydrocholesterol during sun exposure, while, except rarely, it is very scarce in food. Having in mind extensive evidence that sun exposure presents a high risk for the development of skin malignancies, primarily melanoma, it is clear that humans are deprived of the natural and basic source of vitamin D. In accordance, as well as based on numerous epidemiological studies showing the increase of diseases, in the basis of which vitamin D deficiency plays the important role, next led to the recommended dietary allowance of vitamin D, regardless of age. According to current attitudes, it is recommended that the daily dietary allowances of vitamin D, i.e., the quantity of oral intake that would safely cover the optimal body requirements should be 400 IU for ages 0-18 years, 600 IU for ages 19-70 years and 800 IU for persons aged over 70 years.

Infant and fetal vitamin D status and bone health

Recently, considerable interest has been shown in the role of maternal vitamin D status on growth, bone development and mineral homeostasis of the developing fetus, infant and child, especially in view of our better understanding of the possible long-term effects of impaired early growth and development on body composition and bone mass in later life. Although the fetus is to a large extent well protected against the possible deleterious effects of maternal vitamin D deficiency, there is evidence that maternal vitamin D deficiency might result in impaired fetal mineralization and growth. Further maternal vitamin D deficiency increases the risk of neonatal hypocalcaemia and its complications during the first month of life. Maternal vitamin D deficiency is a major risk factor for vitamin D deficiency rickets in the breastfed infant, and thus attention should be paid to ensuring maternal vitamin D sufficiency during pregnancy and preventing vitamin D deficiency in the infant through either maternal or infant vitamin D supplementation. The long-term consequences of maternal vitamin D deficiency during pregnancy are not clearly defined, although some studies have suggested impaired growth during infancy and reduced bone mass in pre-pubertal children. Further research is required to unravel the role of maternal vitamin D not only on children's bone mass and growth but also on the possible non-skeletal effects of vitamin D. The importance of ensuring vitamin D sufficiency in the breastfed infant and methods of achieving this are discussed, and the recently released recommendations of the Institute of Medicine with regard to recommended dietary allowances for vitamin D are placed in context.

Deficiency of Vitamin C in Dairy Products and Supplementation in Milk by Adding the Bioactive Natural Products

Since milk constitutes an important item in the human diet and since the importance of an adequate amount of vitamin C in the diet is becoming more fully appreciated, it appeared to us that any investigation that might yield further information as to how milks containing greater quantities of this dietary essential might be produced would be worth while. Sea buckthorn is a natural multi-vitamins and a major source of vitamin C, fruits containing vitamin C at a rate of two times more than rosehips and ten times more than citrus (200-1500 mg). Strengthening with Vitamin C will be considering of content of vitamin C in milk samples taken per season (winter, spring, summer, autumn). This contributes to a balanced diet need vitamin C content in fruits of sea buckthorn. The new recommended dietary allowance of vitamin C (110 mg per day for an adult) takes into account of risks for health.

Haptoglobin genotype modifies the association between dietary vitamin C and serum ascorbic acid deficiency

Haptoglobin (which is encoded by the Hp gene) is a hemoglobin-binding protein that has antioxidant properties and a common polymorphism that consists of 2 structurally different alleles: Hp1 and Hp2. The capacity of Hp2 to inhibit oxidation and vitamin C depletion is less than that of Hp1, but the influence on vitamin C requirements remains unknown. This study aimed to determine whether the Hp polymorphism modifies the association between dietary vitamin C and serum ascorbic acid deficiency (<11 μmol/L). Nonsmoking men and women (n = 1046) between 20 and 29 y of age participated in the Toronto Nutrigenomics and Health Study. Blood samples were collected after the subjects had fasted overnight to determine serum ascorbic acid concentrations by HPLC and for genotyping. A 196-item food-frequency questionnaire was used to estimate vitamin C intake. A gene-diet interaction on serum ascorbic acid was observed (P = 0.02). The overall odds ratio (95% CI) for serum ascorbic acid deficiency was 2.84 (1.73, 4.65) for subjects who did not meet the Recommended Dietary Allowance for vitamin C compared with those who did. The corresponding odds ratios were 4.77 (2.36, 9.65) for the Hp2-2 genotype and 1.69 (0.80, 3.63) for carriers of the Hp1 allele. Individuals with the Hp2-2 genotype had an increased risk of deficiency if they did not meet the Recommended Dietary Allowance for vitamin C, whereas carriers of the Hp1 allele did not. The findings suggest that the greater antioxidant capacity of Hp1 might spare serum ascorbic acid.

Vitamin A Fortification of Wheat Flour: Considerations and Current Recommendations

Vitamin A deficiency is a major public health nutrition problem, affecting an estimated 190 million preschool-aged children and 19 million pregnant and lactating women globally, and 83 million adolescents in Southeast Asia alone. Its consequences (disorders) include xerophthalmia (the leading cause of early childhood blindness), increased severity of infection, anemia, and death. Because vitamin A deficiency is largely due to chronic dietary insufficiency of preformed vitamin A and proactive carotenoids, food fortification can offer an effective approach to prevention. To provide guidance on fortifying wheat and maize flour milled in industrial rollers for national fortification programs in countries where vitamin A deficiency is considered a public health problem. Critical review of the literature on the dietary gap in vitamin A intake and levels of wheat flour intake among risk groups as a basis for determining vitamin A fortificant levels. Additional review of efficacy evidence, safety and cost considerations, and country experiences related to wheat-flour fortification with vitamin A. Mill-rolled wheat flour is a technically fortifiable, centrally processed food vehicle that, where routinely and adequately consumed by target groups, should be considered a candidate for fortification. Vitamin A can be stable in flour under typical, ambient conditions, with processing losses estimated at approximately 30%, depending on source and premix conditions. Factors to guide a decision to fortify flour with vitamin A include the extent of deficiency, availability of other food vehicle options, the centrality of milling, market reach and population intake distributions of the flour products, the dietary vitamin A intake required, and associated costs. Large gaps persist in knowledge of these factors, which are needed to enable evidence-based fortification in most countries, leaving most decisions to fortify guided by assumptions. Where flour can and should be fortified, guidelines are given for providing nearly 25% of the Recommended Dietary Allowance for vitamin A to vulnerable groups consuming varying ranges of flour products. The costs will vary according to the level of fortification.

Functional genetic variants of glutathione S-transferase protect against serum ascorbic acid deficiency

BackgroundGlutathione S-transferases (GSTs) are detoxifying enzymes that contribute to the glutathione-ascorbic acid (vitamin C) antioxidant cycle. ObjectiveThe objective was to determine whether GST genotypes modify the association between dietary vitamin C and serum ascorbic acid. DesignNonsmoking men and women (n = 905) between 20 and 29 y of age were participants in the Toronto Nutrigenomics and Health Study. Overnight fasting blood samples were collected to determine serum ascorbic acid concentrations by HPLC and to genotype for deletion polymorphisms in GSTM1 and GSTT1 and an Ile105Val substitution in GSTP1. A 196-item food-frequency questionnaire was used to estimate vitamin C intake. ResultsA gene-diet interaction on serum ascorbic acid was observed for GSTM1 (P = 0.04) and GSTT1 (P = 0.01) but not for GSTP1 (P = 0.83). The odds ratio (95% CI) for serum ascorbic acid deficiency (<11 ¼mol/L) was 3.20 (1.88, 5.44) for subjects who did not meet the Recommended Dietary Allowance of vitamin C compared with those who did. The corresponding odds ratios (95% CIs) were 2.17 (1.10, 4.28) and 12.28 (4.26, 33.42), respectively, for individuals with the GSTT1*1/*1 +*1/*0 (functional) and GSTT1*0/*0 (null) genotypes and 2.29 (0.96, 5.45) and 4.03 (2.01, 8.09), respectively, for the GSTM1*1/*1+GSTM1*1/*0 and GSTM1*0/*0 genotypes. ConclusionsThe recommended intake of vitamin C protects against serum ascorbic acid deficiency, regardless of genotype. Individuals with GST null genotypes had an increased risk of deficiency if they did not meet the Recommended Dietary Allowance for vitamin C, which suggests that the GST enzymes protect against serum ascorbic acid deficiency when dietary vitamin C is insufficient.

High prevalence of vitamin D deficiency despite supplementation in premenopausal women with breast cancer undergoing adjuvant chemotherapy.

Vitamin D deficiency is associated with increased breast cancer risk and decreased breast cancer survival. The purpose of this study was to determine the prevalence of vitamin D deficiency, as measured by serum 25-hydroxyvitamin D (25-OHD), in premenopausal women at initiation of adjuvant chemotherapy for breast cancer and after 1 year of vitamin D supplementation. The study included 103 premenopausal women from the northeastern United States with stages I to III breast cancer who received adjuvant chemotherapy and participated in a 1-year zoledronate intervention trial. All patients were prescribed vitamin D(3) (cholecalciferol) 400 IU and calcium carbonate 1,000 mg daily. At baseline and at 6 and 12 months, bone mineral density (BMD) measurements were obtained and blood was collected and analyzed in batches for serum 25-OHD. Vitamin D deficiency was defined as serum 25-OHD less than 20 ng/mL, insufficiency as 20 to 29 ng/mL, and sufficiency as 30 ng/mL or greater. At baseline, 74% of women were vitamin D deficient (median, 17 ng/mL). Vitamin D deficiency was slightly less common in white women (66%) compared with black (80%) and Hispanic (84%) women. After vitamin D supplementation for 1 year, less than 15% of white and Hispanic women, and no black women, achieved sufficient 25-OHD levels. Vitamin D levels did not correlate with baseline BMD and were not altered by chemotherapy or bisphosphonate use. Vitamin D deficiency is highly prevalent in women with breast cancer. The current recommended dietary allowance of vitamin D is too low to increase serum 25-OHD greater than 30 ng/mL. Optimal dosing for bone health and, possibly, improved survival has yet to be determined.

Salad and Raw Vegetable Consumption and Nutritional Status in the Adult US Population: Results from the Third National Health and Nutrition Examination Survey

Objective To examine the relationship between reported salad consumption and serum nutrient levels as well as dietary adequacy, as defined by nutrient intakes, in relation to the National Academy of Science Food and Nutrition Board Guidelines, in pre- and postmenopausal women and in men of comparable ages. Design Analyses of 24-hour recalls were conducted to determine dietary intake using the Third National Health and Nutrition Examination Survey data. Salad consumption was assessed based on intakes of salad, raw vegetables, and salad dressing. Subjects Nine thousand four hundred-six women and 8,282 men aged 18 to 45 years and older than 55 years were examined between 1988 and 1994. Statistical Analyses Regressions were used to model associations between salad and raw vegetable consumption and selected serum nutrient outcomes. Usual nutrient intake distributions were estimated using the Iowa State University method for adjustment of the distribution. The Estimated Average Requirement method was used to determine the proportion of subjects with inadequate intake for each nutrient. Results The consumption of salads, raw vegetables, and salad dressing was positively associated with above-median serum micronutrient levels of folic acid, vitamins C and E, lycopene, and α- and β-carotene. Each serving of salad consumed was associated with a 165% higher likelihood to meet the recommended Dietary Allowance for vitamin C in women and 119% greater likelihood in men. Conclusions Salad consumers tended to have more favorable intakes of vitamins C and E, folic acid, and carotenoids, after adjustment for other differences. The significant and consistently higher serum values of these vitamins among salad consumers suggest that they are being well absorbed from salad. Salad, salad dressing, and raw vegetable consumption can be an effective strategy for enhancing nutritional adequacy and increasing vegetable consumption in the population at large.

The Effects of Dieting on Food and Nutrient Intake of Lactating Women

The purpose of this report was to identify and evaluate dietary changes in women who were participating in a study on the effects of weight loss in overweight lactating women on the growth of their infants. Women were randomly assigned at 4 weeks postpartum to either restrict energy intake by 500 kcal/day (diet and exercise group) or to maintain usual dietary intake (control group) for 10 weeks. The diet and exercise group significantly decreased fats, sweetened drinks, sweets and desserts, snack foods, and energy intake. Micronutrient intake decreased in the diet and exercise group; however, mean intakes were not significantly different from those of the control group except for calcium and vitamin D. Both groups consumed less than 76% of the Recommended Dietary Allowance for vitamins E and C at the end of the study. Mean intake of all other nutrients was adequate in both groups. These results suggest that overweight lactating women can restrict their energy intake by 500 kcal per day by decreasing consumption of foods high in fat and simple sugars. However, they must be advised to increase their intakes of foods high in calcium and vitamin D. Increased intake of fruits and vegetables should also be recommended to all lactating women, as well as multivitamin and calcium supplements to those who do not consume adequate amounts of these foods.

Children of Latino Immigrants, 4-8 Years, in Rural Nebraska are Adequate in Vitamin B-6

Plasma concentrations of B-6 vitamers and homocysteine as well as erythrocyte alanine aminotransferase activity coefficients and vitamin B-6 (dietary + supplement) intakes of apparently healthy young Latino children of immigrant parents living in rural Nebraska were determined and differences determined by gender. Thirty-five Latino children (16 males and 19 females), aged 4-8 years, were included in the study. Nutrient intake information was obtained from the children's parents utilizing two nonconsecutive 24-hour food recalls. No differences were observed by gender with regard to vitamin B-6 intakes, plasma concentrations of B-6 vitamers and homocysteine, and erythrocyte alanine aminotransferase activity coefficients. The intakes of all children met the Recommended Dietary Allowance for vitamin B-6. Plasma pyridoxal 5'-phosphate concentrations, plasma homocysteine concentrations, and erythrocyte alanine aminotransferase activity coefficients of the children were (mean +/- SD) 83.71 +/- 37.35 nmol/L, 6.81 +/- 1.63 micromol/L, and 1.08 +/- 0.06, respectively. All the Latino children of immigrant parents in this study had values indicative of adequate vitamin B-6 status.

Improving the Nutritional Value of Crops through Enhancement of l-Ascorbic Acid (Vitamin C) Content: Rationale and Biotechnological Opportunities

L-Ascorbic acid (AsA, vitamin C) is an essential human nutrient that must be obtained in the diet, with the vast majority being obtained from plant foods. A vitamin C-deficient diet results in the onset of scurvy, which can have lethal consequences. However, vitamin C has also been implicated in the prevention of chronic diseases such as heart disease, stroke, cancer, and several neurodegenerative diseases. Although the supporting evidence for these claims is disputed, the dietary allowances for vitamin C have been recently increased in several countries, including the United States. This scenario, together with the general perception by consumers of vitamin C as being of benefit in the prevention of several lifestyle diseases and associated with general "well-being", contributes to a market rationale for enhancing the vitamin C content of crops. In recent years, there has been substantial progress in the understanding of vitamin C biochemistry in plants with a number of structural genes cloned. Here these findings are reviewed, and a description of how such knowledge could be applied to the nutritional enhancement of crops is given.

Issues in establishing vitamin D recommendations for infants and children

In 1963, the American Academy of Pediatrics Committee on Nutrition recommended 400 IU of vitamin D per day for all infants and children. After the late 1970s, this became an inconsistent recommendation, particularly for breast-feeding infants. In 2003, however, the Committee on Nutrition of the American Academy of Pediatrics recommended 200 IU/d vitamin D for all infants and children. This was in response to the vitamin D adequate intake recommendations made by the Institute of Medicine in 1997, the increasing number of reports of nutritional rickets in certain populations of American infants, and the Healthy People 2010 goal of having 75% of infants breast-fed for the first 6 mo of life. In making these recommendations, many issues were taken into consideration, including the following. 1) Vitamin D deficiency is more than rickets, which is the final stage of the deficient state among growing children. 2) Adequate sunlight exposure cannot be determined exactly for every subject. 3) There is new awareness of the hazards of ultraviolet-B light exposure in childhood and the subsequent development of skin cancer in adulthood. 4) There is decreasing intake of vitamin D-fortified foods among older children and adolescents. More research is needed in the pediatric population to determine the recommended dietary allowance of vitamin D. A new definition of vitamin D deficiency that would make use of normal serum concentrations of 25-hydroxyvitamin D3 in a given population is needed. The recommended intake of 200 IU/d may not be enough. More data are needed to support the adequacy of the present and possibly even higher recommended vitamin D daily intakes.

Association of fish and fish liver oil intake in pregnancy with infant size at birth among women of normal weight before pregnancy in a fishing community.

This 1998 study investigated the association between intake of fish and fish oil during pregnancy and full-term infants' size at birth in an Icelandic fishing community. Healthy women aged 20-40 years of normal weight before pregnancy (body mass index: 19.5-25.5 kg/m(2)) and at 38-43 weeks of gestation were selected randomly. Information on infant size at birth was collected from maternity records. Intake of fish and fish oil in pregnancy was ascertained (n = 491, 80.1%) by using a validated, focused, food frequency questionnaire. Infants of women in the lowest quartile of fish consumption weighed less (p = 0.036), were shorter (p < 0.001), and had a smaller head circumference (p < 0.001) at birth than those of women consuming higher amounts of fish. Infants of women in the highest quartile of fish oil intake (> or =1 tablespoon (11 ml)/day), consuming threefold the recommended dietary allowance of vitamin A and twofold that of vitamin D, were shorter (p = 0.036) and had a smaller head circumference (p = 0.003) than those of women consuming less. Infant size at birth increased with fish consumption, especially for women in the lower quartiles of consumption. Smaller birth size was linked to the highest levels of fish oil intake. Constituents of fish and fish oil might affect birth size differently depending on the amount consumed.

Recommended dietary allowance for vitamin C in the United States is also applicable to a population of young Japanese women

The recommended dietary allowance (RDA) for ascorbic acid (AA) in Canada and the United States has been set for several years at 75 mg/day for women 19-30 years old. Recently this level was questioned, and an increase to 90 mg/day was suggested. For Japanese women in the same age group, we found that the RDA for AA is currently 100 mg/day. Our goal was to determine which RDA is sufficient for maintaining a serum concentration of AA in young Japanese women above the lower reference limit of 7.0 mg/L. We measured serum AA concentrations by an ascorbate oxidase method in 176 healthy Japanese women (19-26 years old). We also performed an ROC analysis to estimate the optimal cutoff value for oral dosage to distinguish individuals with hypovitaminosis-C (<7.0 mg/L) from those with a normal serum AA. We evaluated the Japanese RDA using the 75 or 90 mg/day U.S. RDA and the weight ratio between Japanese and U.S. women, and discovered that the RDA value ranged between 66 and 79 mg/day. From the ROC analysis, we found that the optimal daily dosage of AA is approximately 75 mg/day. This value gave the highest efficiency, sensitivity, negative predictive value, and positive likelihood ratio, and the lowest negative likelihood ratio. Therefore, an RDA of 100 mg/day may be unnecessarily high for young Japanese women.

The Influence of Sweetened Drink Consumption on the Likelihood of Meeting the Recommended Dietary Allowance for Vitamins and Minerals

Per capita consumption of regular (sugared) soft drinks increased 86% between 1970 and 1997. It has been suggested that they may pose health risks if they replace more nutrient‐dense foods and beverages. The probability of meeting the recommended dietary allowance (RDA) threshold for vitamins and minerals is modeled as a function of individual characteristics including the proportion of food energy received from sweetened drinks. For all vitamins and minerals studied, an increase in consumption of food energy from sugared drinks was significantly associated with a reduced probability of meeting the RDA. Results suggest a tendency to substitute sugared drinks for more nutrient‐dense foods and beverages, leading to an overall reduction in micronutrients.

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Micronutrients and genomic stability: a new paradigm for recommended dietary allowances (RDAs)

Diet as a key factor in determining genomic stability is more important than previously imagined because we now know that it impacts on all relevant pathways, namely exposure to dietary carcinogens, activation/detoxification of carcinogens, DNA repair, DNA synthesis and apoptosis. Current recommended dietary allowances for vitamins and minerals are based largely on the prevention of diseases of deficiency such as scurvy in the case of vitamin C. Because diseases of development, degenerative disease and aging itself are partly caused by damage to DNA it seems logical that we should focus better our attention on defining optimal requirements of key minerals and vitamins for preventing damage to both nuclear and mitochondrial DNA. To date, our knowledge on optimal micronutrient levels for genomic stability is scanty and disorganised. However, there is already sufficient evidence to suggest that marginal deficiencies in folate, vitamin B12, niacin and zinc impact significantly on spontaneous chromosome damage rate. The recent data for folate and vitamin B12 in humans with respect to micronucleus formation in blood and epithelial cells provide compelling evidence of the important role of these micronutrients in maintenance of genome integrity and the need to revise current RDAs for these micronutrients based on minimisation of DNA damage. Appropriately designed in vitro studies and in vivo placebo controlled trials with dose responses using a complementary array of DNA damage biomarkers are required to define recommended dietary allowances for genomic stability. Furthermore these studies would have to be targeted to individuals with common genetic polymorphisms that alter the bioavailability of specific micronutrients and the affinity of specific key enzymes involved in DNA metabolism for their micronutrient co-factor. That there is a need for an international collaborative effort to establish RDAs for genomic stability is self-evident.

The correlates of dietary intake among HIV-positive adults

Dietary adequacy, as distinct from weight loss, has not been examined thoroughly in a diverse cohort of HIV-infected individuals. An analysis was undertaken to determine the correlates of inadequate dietary intake among HIV-infected adults. In a cross-sectional study of 463 men and 170 women (aged 21-70 y) with HIV infection, dietary adequacy was evaluated by using 3-d diet records. Among nondieting males, whites had higher energy intakes than did nonwhites. Injection drug users consumed less energy than did nonusers. Among nondieting females, only the absence of nausea and vomiting was marginally associated with higher energy intakes. Inadequate energy intake, which occurred in 38% of this population, was independently associated with female sex among nondieters. A significant proportion of the study cohort (52%) was consuming less than the recommended dietary allowance of vitamin A. Inadequate protein intake, found in 11% of the study population, occurred more often in females, those without a caregiving adult in the household, and individuals with reduced appetite. A considerable proportion of the participants (23%) reported that they were dieting to lose weight. Dietary inadequacy was strongly correlated with being in the sociodemographic groups that are at heightened risk of adverse clinical outcomes. It may be worthwhile to study dietary intake as a potential determinant of the clinical outcomes of HIV infection.

A new recommended dietary allowance of vitamin C for healthy young women.

The recently released Recommended Dietary Allowance of vitamin C for women, 75 mg daily, was based on data for men. We now report results of a depletion-repletion study with healthy young women hospitalized for 186 +/- 28 days, using vitamin C doses of 30-2,500 mg daily. The relationship between dose and steady-state plasma concentration was sigmoidal. Only doses above 100 mg were beyond the linear portion of the curve. Plasma and circulating cells saturated at 400 mg daily, with urinary elimination of higher doses. Biomarkers of endogenous oxidant stress, plasma and urine F(2)-isoprostanes, and urine levels of a major metabolite of F(2)-isoprostanes were unchanged by vitamin C at all doses, suggesting this vitamin does not alter endogenous lipid peroxidation in healthy young women. By using Food and Nutrition Board guidelines, the data indicate that the Recommended Dietary Allowance for young women should be increased to 90 mg daily.