Considerations in planning vegan diets: children.

This article reviews research on the growth and nutrient intake of vegan children and provides guidelines for counselling parents of vegan children. Although diets of vegan children meet or exceed recommendations for most nutrients, and vegan children have higher intakes of fiber and lower intakes of total fat, saturated fat, and cholesterol than omnivore children, some studies indicate that they may be low in calcium. In addition, bioavailability of zinc and iron from plant foods can be low. Protein needs are slightly higher for vegan children but are easily met with a varied diet that provides adequate energy. Special attention should be given to dietary practices that enhance absorption of zinc and iron from plant foods. Further, good sources of the omega-3 fatty acid linolenic acid should be emphasized to enhance synthesis of the long-chain fatty acid docosahexanoic acid. Dietetics professionals who counsel vegan families should help parents identify good sources of vitamin B-12, riboflavin, zinc, calcium and, if sun exposure is not adequate, vitamin D. This should not be problematic, due to the growing number and availability of fortified vegan foods that can help children meet all nutrient needs. Therefore, with appropriate food choices, vegan diets can be adequate for children at all ages.

Considerations in planning vegan diets: infants.

Appropriately planned vegan diets can satisfy nutrient needs of infants. The American Dietetic Association and The American Academy of Pediatrics state that vegan diets can promote normal infant growth. It is important for parents to provide appropriate foods for vegan infants, using guidelines like those in this article. Key considerations when working with vegan families include composition of breast milk from vegan women, appropriate breast milk substitutes, supplements, type and amount of dietary fat, and solid food introduction. Growth of vegan infants appears adequate with post-weaning growth related to dietary adequacy. Breast milk composition is similar to that of non-vegetarians except for fat composition. For the first 4 to 6 months, breast milk should be the sole food with soy-based infant formula as an alternative. Commercial soymilk should not be the primary beverage until after age 1 year. Breastfed vegan infants may need supplements of vitamin B-12 if maternal diet is inadequate; older infants may need zinc supplements and reliable sources of iron and vitamins D and B-12. Timing of solid food introduction is similar to that recommended for non-vegetarians. Tofu, dried beans, and meat analogs are introduced as protein sources around 7-8 months. Vegan diets can be planned to be nutritionally adequate and support growth for infants.

Determinants of plasma vitamin E in healthy males.

Vitamin E or tocopherol, a known antioxidant, may play a role in the etiology of chronic diseases such as cancer and heart disease. This study examined both "internal" (lipids, lipoproteins, and apoproteins) and "external" (dietary components, physical activity, and body mass index) factors which may influence plasma alpha-tocopherol and gamma-tocopherol levels. Analyses were done using dietary questionnaires and plasma obtained from 65 nonsmoking male volunteers aged 30-59 years. Forty-six men did not take any supplements while 19 took supplements containing vitamin E. A positive correlation (r = 0.32; P < 0.01) between vitamin E intake and alpha-tocopherol status [(ratio of plasma alpha- or gamma-tocopherol/(total triglycerides + total cholesterol)] and a negative correlation (r = -0.33; P < 0.007) between intake and gamma-tocopherol status were observed. The main internal factors, or determinants, for plasma alpha-tocopherol for nonsupplement users were plasma triglycerides and apoproteins, apoA1 and apoB, but neither lipids nor apoproteins appeared to affect tocopherol levels in supplement users. External determinants of alpha-tocopherol status in nonsupplement users were vitamin E intake, total fat intake, and body mass index, while in supplement users only vitamin E intake was important. Both vitamin E intake and alcohol intake appeared to affect plasma gamma-tocopherol status in a negative manner.

Utilization of two different chemical forms of selenium during lactation using stable isotope tracers: an example of speciation in nutrition.

The bioavailability and metabolism of different chemical species of mineral nutrients in the diet are receiving much attention from research nutritionists. In order to make scientifically based recommendations for mineral intakes, the chemical form of the mineral, with its specific absorption, utilization and retention, needs to be considered. Selenium is an example of an essential nutrient that is consumed in several different chemical forms, hence information is needed on the bioavailability and metabolism of each form before recommendations for dietary intakes can be made. A valuable tool for research on bioavailability and metabolism in humans is stable isotope tracers. When there are more than two stable isotopes available, as with selenium, stable isotope methodology allows the comparison of the utilization of different chemical forms of the nutrient simultaneously in in vivo studies. As an example of speciation questions addressed by nutritionists, a study is described that simultaneously evaluated utilization (absorption, retention and appearance in milk and blood) of two different chemical forms of selenium (selenite and selenomethionine) in lactating, non-lactating and never pregnant women using stable isotope tracers. All three groups of women had similar selenium status at the start of the study. Significantly more selenium from selenomethionine than from selenite was absorbed and appeared in the plasma in all groups. Milk contained more selenium from apparently absorbed selenomethionine than from selenite. All groups retained significantly more selenium from selenomethionine than from selenite; lactating women retained more selenium from selenite than did the other two groups, suggesting that milk losses may be partially compensated by enhanced retention of dietary selenium as selenite.(ABSTRACT TRUNCATED AT 250 WORDS)

Selenium utilization during human lactation by use of stable-isotope tracers.

We examined utilization of selenomethionine (SeMet) and selenite in six lactating (L) and six nonlactating (NL) women, 2-3 mo postpartum, and seven never-pregnant (NP) women by use of stable-isotope tracers. All groups had similar selenium status at the start of the study. Significantly more selenium from SeMet than from selenite was absorbed and appeared in plasma in all groups. Milk contained more selenium from apparently absorbed SeMet than from selenite. More selenium from apparently absorbed selenite than from SeMet appeared in urine of NP and NL subjects whereas L subjects had approximately the same amount of selenium from apparently absorbed selenite and SeMet in their urine. All groups retained significantly more selenium from SeMet than from selenite; L women retained more selenium from selenite than did the other two groups. Absorption and retention of selenium from SeMet in L women did not appear to be significantly different from that in other women, suggesting that selenium requirements during lactation are increased mainly because of milk losses.

Vitamin B-6 intakes of lactating women: analyzed vs calculated values.

Results of our study suggest that calculation of vitamin B-6 content of diets using a current database can provide a reasonably good estimation of the vitamin B-6 intakes of a population of lactating women. Our study also demonstrates that the mean vitamin B-6 intake of this group of lactating women 2 months after they had given birth, who were not using vitamin B-6 supplements, was 1.45 mg, which is less than 70% of the RDA. However, on the basis of guidelines for the assessment of vitamin B-6 status using dietary vitamin B-6:protein ratio (15,20), the women appeared to be consuming adequate amounts of vitamin B-6.