Association between dietary fiber intake and the folate status of a group of female adolescents.

The main objective of this study was to assess the association between dietary fiber intake and the folate status of Canadian female adolescents. We also assessed dietary folate intakes and evaluated the prevalence of biochemical folate deficiency in these subjects. Female adolescents aged 14-19 y (n = 224) were recruited and fasting blood samples were collected. Dietary intakes (3-d food record) were recorded and participants were classified as lactoovovegetarians, semivegetarians, or omnivores on the basis of food-consumption patterns assessed with food-frequency questionnaires. Fourteen percent, 17%, and 26% of lactoovovegetarians, semivegetarians, and omnivores, respectively, had dietary folate intakes below their predicted requirements; 1%, 4%, and 23%, respectively, had serum folate concentrations indicative of deficiency. Despite low dietary folate intakes and serum folate concentrations, few subjects had homocysteine concentrations indicative of deficiency, suggesting that the degree of folate depletion had not yet produced functional consequences. Most important, results suggest that the consumption of nonstarch polysaccharide is significantly associated with serum folate concentrations (P < 0.001). For each 1-g increase in nonstarch polysaccharide intake, a 1.8% increase in serum folate concentration is expected. In summary, we propose that an increase in nonstarch polysaccharide intake may promote the intestinal biosynthesis of folate, providing a complementary strategy to enhance the folate nutriture of humans.

Dietary intakes of adolescent females consuming vegetarian, semi-vegetarian, and omnivorous diets.

PURPOSE: To determine the energy and nutrient intakes of some omnivorous and vegetarian female adolescents to compare their risk for nutrient inadequacies. METHODS: A convenience sample of 78 lacto-ovo-vegetarians (LOV), 15 semi-vegetarians (SV), and 29 omnivorous (OM) females aged 14-19 years completed three-day weighed records from which mean intakes and major food sources of energy, nutrients, and dietary fiber (as nonstarch polysaccharides (NSP)) were calculated. RESULTS: Mean daily intakes for energy and most nutrients were comparable for the three groups although LOV had higher intakes (p < 0.01) of NSP, copper, and manganese. Lacto-ovo-vegetarians consumed (g/d) less dairy products, flesh foods, and sweets but more legumes, nuts, and vegetables. Major food sources were cereal products for energy, most nutrients, NSP, dairy products for calcium, and fruits and vegetables for vitamin C. More LOV and SV had energy intakes less than two-thirds of Canadian recommendations, and higher probability estimates of inadequacy for protein, calcium, iron, zinc, and riboflavin than OM. Fewer LOV (35%) than SV (53%) and OM (41%) had diets with less than 30% energy from fat. CONCLUSIONS: LOV and SV were more at risk for nutrient inadequacies than OM, although about 33% of OM were also at risk for inadequate intakes of iron and zinc.

Iron and zinc status of young women aged 14 to 19 years consuming vegetarian and omnivorous diets.

OBJECTIVE: To assess the iron and zinc status of young females, aged 14 to 19 years, consuming vegetarian and omnivorous diets. METHODS: Dietary intakes (via 3-day weighed food records), BMI, and laboratory indices of iron and zinc status were compared in a convenience sample of 79 lacto-ovo-vegetarians (LOV), 16 semi-vegetarians (SV), and 29 omnivorous (OM) females. RESULTS: Twenty-nine percent LOV, 44% SV, and 17% OM had low iron stores (i.e., plasma ferritin < 12 micrograms/L); only 3% had anemia. As well, 24% LOV, 33% SV, and 18% OM had serum zinc < 10.71 mumol/L and 14% LOV, 14% SV, and 17% OM had hair zinc < 1.68 mumol/g. Intakes of iron and ascorbic acid from the weighed food records were associated with serum iron (p < 0.04) and total iron binding capacity (negatively; p < 0.02), respectively, whereas Phy:Zn molar ratios were associated with serum zinc (negatively; p < 0.04). Z-scores for BMI were associated with serum zinc (p < 0.02) and diet type (p < 0.001); serum AP activity was associated with age (p < 0.0001) and oral contraceptive use (p < 0.04). CONCLUSIONS: Suboptimal iron and zinc status was attributed to low intakes of poorly available iron and zinc in all dietary groups.

Dietary strategies to improve the iron and zinc nutriture of young women following a vegetarian diet.

Dietary strategies to enhance the content and bioavailability of iron and zinc in vegetarian diets were compiled. Strategies included increasing promoters and decreasing antagonists of iron and zinc absorption, adopting food preparation and processing methods which hydrolyze the phytate content of cereals and legumes, and using iron cookware. These strategies were used to devise two vegetarian menus based on food consumption patterns derived from three day weighed food records of 78 Canadian lacto-ovo-vegetarian adolescents. The iron and zinc, as well as calcium, phosphorus, thiamin, riboflavin, niacin, vitamin A, protein and energy content of the devised menus were all higher than the actual intakes and the corresponding Canadian recommended nutrient intakes. Results show the overall nutrient adequacy of the recommended vegetarian menus and indicate that young lacto-vegetarian women can potentially meet their estimated dietary requirements for absorbed iron and zinc through modest modifications to the diet. Laboratory studies designed to measure the total amount of iron and zinc absorbed from these diets by young vegetarian women are needed to verify the efficacy of the devised menus.

Selenium intakes of children from Malawi and Papua New Guinea consuming plant-based diets.

Dietary selenium intakes were determined over three seasons for 66 children aged 4-6 y in rural Malawi, and at one season for 67 children aged 6-10 y in rural Papua New Guinea. The selenium content of the foods consumed was assessed using instrumental neutron activation analysis. Median intakes of selenium for the Malawian children were 20 micrograms per day, 21 micrograms per day, and 15 micrograms per day at harvest, postharvest, and preharvest seasons, respectively. More than 43% of the Malawian intakes were below the U.S. Recommended Dietary Allowances for 4-6 y olds (20 micrograms per day). Median intake of Se for the Papua New Guinean children was 20 micrograms per day, with 87% of the intakes below the recommended level for 7-10 y olds (30 micrograms per day). Statistical comparisons of selenium intakes over three seasons for the 51 children present in all survey periods revealed that mean intakes were not significantly different in survey periods one and two, but decreased significantly in survey period three, when expressed per day (p less than 0.002), per MJ (p less than 0.003), or per kg (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)