Vitamin requirements for term infants: considerations for infant formulae

Abstract

Objective. To provide the informed health professional with an up to date evaluation of the current thinking regarding requirements for vitamins in infant feeds. Establishing criteria for adequacy. Vitamin adequacy in the neonate is currently defined in terms of circulating levels of a vitamin or of the activity of a vitamin dependent enzyme in the erythrocytes. Although these measurements have their value there is a need to develop biochemical, physiological or clinical markers of well defined specific function. For some vitamins there is a risk of deleterious effects of very high intakes: risk of toxicity needs to be taken into consideration when making recommendations for inclusion in infant formulae. Breast milk as the 'gold standard'. Breast milk concentrations of vitamins have been used as the criteria of adequate intake by neonates. This may not always be justified. Greater consideration needs to be given to differences in bioavailability of vitamins from breast milk compared with formula feeds, of the influence of season, and of stage of lactation, on the stated composition. Experimental approaches. Animal studies have provided limited information regarding effects of different levels of intakes on current status indices in the neonatal period. There are few reports of randomized controlled studies into the effects of different levels of vitamins and these rely heavily on biochemical criteria of adequacy. Recent developments. The inclusion of fl-carotene into formula feeds for premature babies is an issue of current interest. What is the justification for this? Are there potential benefits for the term infant? Riboflavin deficiency in the period around weaning may affect the normal structural and functional development of the gastrointestinal tract; some. of these effects may be permanent. Research to be done. A greater understanding of the absorption and metabolism of vitamins during infancy is required in order to help establish dietary requirements. The relative bioavailability of vitamins in human milk and formulae needs to be investigated. Criteria for vitamin adequacy should be extended to include measures of function. Information regarding the conversion factor from tryptophan to niacin in infancy would allow us to set niacin requirements with greater confidence. There is a particular lack of information about concentrations of biotin and pantothenic acid in breast milk and the relative biochemical status of infants receiving breast milk and formulae. Benefits of including fi-carotene into infant formulae need to be evaluated. The role of individual micronutrients in the structural and functional development of the gastrointestinal tract should be explored.

Vitamins for babies and young children

“…Water-soluble vitamins-B group and Care actively transported across the placenta throughout pregnancy, whereas fat-soluble vitamins A, D and E are transferred towards the end of pregnancy. There is negligible transfer of vitamin K. 6 Breast milk from mothers with adequate status supplies sufficient amounts of most vitamins apart from vitamins K and D. Thus, unsupplemented infants depend on synthesis of vitamin K by gut bacteria, and on antenatally acquired hepatic stores of vitamin D as well as cutaneous synthesis in response to sunlight. 6 Table 2 lists the reference nutrient intakes (RNIs) 7 8 for infants.…”

“…There is negligible transfer of vitamin K. 6 Breast milk from mothers with adequate status supplies sufficient amounts of most vitamins apart from vitamins K and D. Thus, unsupplemented infants depend on synthesis of vitamin K by gut bacteria, and on antenatally acquired hepatic stores of vitamin D as well as cutaneous synthesis in response to sunlight. 6 Table 2 lists the reference nutrient intakes (RNIs) 7 8 for infants. The RNI is set at 2 standard deviations (SD) above the estimated average requirement and represents the amount estimated to prevent deficiency in 97.5% of a healthy population.…”

“…It is recognised that the milieu of infant formula and its effect on intestinal function may alter the efficiency with which nutrients are absorbed and used compared with those in breast milk. 6 Simple compositional comparisons are not necessarily reliable as a basis for assessment of nutritional adequacy.…”

Do we really know vitamin and mineral requirements for infants and children?

“…In industrialised countries there is a two-to three-fold variation in the mean breast milk concentration of water-soluble vitamins (the B vitamins and vitamin C), a two-fold variation in vitamin A, eight-to nine-fold for vitamins E and K, and the vitamin D content ranges from undetectable to 2 µg/l. If the well-fed mother is provided with supplements then there is a significant increase in the milk content; 30% to 150% for water-soluble vitamins and vitamin E, two-fold for vitamin K and 90-fold for vitamin D. 7 In less developed countries, where the mother may be inadequately supplied with vitamins and minerals, the breast milk content may be inadequate to meet the infant's needs. Although the thiamin (vitamin B1) content of breast milk from mothers with low intakes is close to that seen in developed countries, acute infantile beriberi, which is rapidly fatal, occurs when the mother is thiamin deficient.…”

Essential vitamins deficiency in children under one year

“…Плод может получить большинство витаминов от своей матери. Водорастворимые витамины группы В и С активно транспортируются через плаценту на протяжении всей беременности, тогда как жирорастворимые витамины А, D и Е -к концу беременности [3,4]. Для обеспечения нормального развития ребенка необходимо адекватное поступление в организм макронутриентов, макро-и микроэлементов.…”