by Mikel Mon Jan 31, 2011 8:24 am
PROTEIN. A safe protein intake level for adults is defined as the lowest level of dietary protein intake that will balance the losses of nitrogen from the body in persons maintaining energy balance at modest levels of physical activity (FAO/WHO/UNU, 1985). The recommended intake levels for children are based on the safe level of protein intakes estimated by the FAO/WHO/UNU (1985) for a reference protein (egg or milk) adjusted for the protein quality of Filipino rice-based diets of 70% protein digestibility corrected amino acid score (PDCAAS). These values are very close to estimates obtained from direct studies on Filipinos consuming usual rice-based diets.
VITAMIN A. The recommended intake levels for vitamin A correspond to the safe levels of intake based on the average amounts of vitamin A required to maintain a given body-pool size in well-nourished individuals. For adults, the RNI is equivalent to the estimated average requirement plus 2SDs. When recommendation for children are estimated by extrapolation from adult recommendations, the resulting values are lower than the reported intakes of children, 0 to 6 y in populations where evidence of vitamin A deficiency (VAD) is rare. The Committee therefore adopts the higher recommendation given by the FAO/WHO (2002).
VITAMIN C. The 1989 RDA which was based on the amount that would maintain “acceptable†serum vitamin C levels in Filipino men and women, is retained. These values are higher than the FAO/WHO RNI which is based on intake associated with adequate liver stores and associated with antioxidant protection. The recommendations for children, 1-9 y, are based on the 2002 FAO/WHO RNIs, while those for older children are extrapolated from adult values.
THIAMIN (VITAMIN B1). The Institute of Medicine, Food and Nutrition Board (IOM-FNB) (1998) and FAO/WHO (2002) recommendations, which are both based on the average requirement for normal erythrocyte transketolase (ETK) activity and urinary thiamin excretion and twice an assumed CV of 10% to cover the needs of 97.5% of individuals in the group, are adopted. The IOM-FNB and FAO/WHO-derived estimates, adjusted for Philippine reference body weighs, are similar to the 1989 RDAs which were then based on a local study done in the '60s on 10 adult Filipinos. The recommended intake level for infants from birth to six months is based on the reported mean thiamin content of breast milk obtained from mothers without beriberi. It may be necessary to give supplements as a protective measure against infantile beriberi.
RIBOFLAVIN (VITAMIN B2). The RNI is derived from the requirement estimate of the IOM-FNB (1998) which is based on the amount of riboflavin intake to maintain riboflavin status of satisfactory erythrocyte glutathione reductase activity (EG-AC) level, as criterion of adequacy. These intake levels, which conform with the FAO/ WHO (2002) recommendations, are close to the 1989 recommendations which were based on requirement estimates obtained from Filipino adults consuming rice-based diets.
NIACIN. The FAO/WHO (2002) and IOM-FNB (1998) estimates, which are based on the amount of niacin intake corresponding to an excretion of N'methyl-nicotinamide that is above the minimal excretion at which deficiency symptoms occur, are also adopted for Filipinos. These values are lower than the 1989 RDA because no correction is made for bioavailability. The bioavailability of niacin is not considered in setting the RDA because of "lack of data on which to base the correction value" (IOM-FNB), 1998.
FOLATE. The FAO/WHO (2002) and IOM-FNB (1998) recommendations are also adopted for Filipinos. The requirement estimates of these two bodies are derived from the amount of folate that will maintain adequate folate stores based on erythrocyte folate and plasma homocysteine levels. To meet the new higher recommendations, higher intakes of vegetables and fruits, which are among the best sources of folate, are recommended.
CALCIUM. The RNIs for Filipinos are allowances based on theoretical calcium requirement estimates which considered low animal protein intake levels. The FAO/WHO (2002) provided these estimates for possible application to countries where the animal protein intake per capita is around 20-40 g only compared with 60-80 g in developed countries. These allowances take into account the need to protect children in whom skeletal needs are much more important determinants of calcium requirement than are urinary losses and in whom calcium supplementation has been found to have a beneficial effect in children accustomed to low calcium intakes.
IRON. The recommended intake for iron is based on the amount of dietary iron needed to meet absorbed iron requirements. This would correspond to the amount needed to cover basal losses plus growth for children and menstrual losses for women of reproductive age, adjusted for bioavailability of iron in typical complete meals consumed by Filipinos. The Philippine RNI for iron is based on FAO/WHO (2002) estimates for basal losses, local data on menstrual losses and on bioavailability, iron absorption rates in the average Filipino diets, food consumption surveys, and in-vitro studies on non-heme iron availability from rice-based diets. For infants, it is assumed that the iron provided by breast milk is adequate to meet the iron needs of infants exclusively fed human milk from birth to 6 mo. The consumption of iron-rich foods and iron-fortified foods is recommended for women from adolescence onwards. Iron supplementation is recommended to meet the needs of pregnant and lactating women. The estimated iron requirement during the first trimester of pregnancy and the first six months of lactation are actually lower than the requirement for menstruating non-pregnant, non-lactating women. However, the recommended intake for non-pregnant and non-lactating women are adopted to allow for build-up of iron stores during these periods.
IODINE. The FAO/WHO (2002) recommendations which concur with those of the IOM-FNB are adopted for all population groups, except pregnant and lactating women. The recommended intake level for adults corresponds to the intake necessary to maintain plasma iodide level above the critical limit likely to be associated with the onset of goiter. It corresponds to the daily iodine urinary excretion of 100 µg/L.
The recommended energy and nutrient intakes levels of the above nutrients are summarized in Table 2
DESIRABLE CONTRIBUTION OF CARBOHYDRATES, FATS AND PROTEIN
Carbohydrates 55-70%
Fats and fatty acids 30-40% for infants
20-30% for all others
Protein 10-15%
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...jan. -__-;;
