Vitamin A deficiency is considered one of the most important of the easily preventable public health problems in a number of countries, including Brazil. The objective of this study was to review the scientific literature in the MEDLINE and LILACS databases that was published between 1970 and 2000 concerning vitamin A deficiency, and to assess the occurrence of hypovitaminosis A in Latin America, especially Brazil. Our research showed that until around 1980 the public health concerns focused mainly on the importance of vitamin A in ensuring good vision. In the second half of the 1980s, epidemiological studies suggested that, on a population level, subclinical vitamin A deficiency could also have a negative effect on metabolic functions, with a great impact on childhood morbidity and mortality. Marginal vitamin A deficiency has been reported in all the regions of Brazil for which there are data available, with high prevalences in various age groups. This situation is inexcusable, given the health care technology and resources that are now available. There must be a commitment to reducing vitamin A deficiency in order to ensure the adequate development of future generations.

Vitamin A status was determined using fasting plasma levels and the relative dose response (RDR) procedure before and 30, 120, and 180 days after administration of an oral massive (200,000 IU) dose of vitamin A. The study was carried out in Recife, Brazil among 93 children of 7 yr or less from low income families who attended two day-care programs. The RDR procedure is conducted by obtaining a fasting blood (A0), feeding 450 retinol equivalents and obtaining a second blood specimen after 5 h (A5). The RDR-(A5-A0)/A5 X 100. A single massive oral dose of vitamin A was given after conducting the base-line RDR test. The RDR procedure was repeated at 30, 120, and 180 days. Weight and height measurements were obtained at each observation and the bloods were analyzed for Hb, total protein, and serum iron, as well as vitamin A. Serum albumin was determined in 120- and 180-day bloods. Serum iron levels were improved 30 days after supplementation with the massive dose of vitamin A. The RDR procedure was found practical to apply in mildly undernourished children under nonclinical condition. In this group of low income children presumed to be habitually ingesting minimally adequate diets, a serum vitamin A level of 20 micrograms/dl or less invariably was associated with an elevated RDR test. Blood levels between 20 to 40 micrograms/dl were not consistently predictive of the RDR response. All elevated RDR tests reverted to normal after supplementation with vitamin A, presumably indirectly indicating a presupplementation inadequate vitamin A status. Hence, the RDR was a more sensitive indicator of inadequate vitamin A status than was only a serum level of vitamin A when blood levels were above 20 micrograms/dl.(ABSTRACT TRUNCATED AT 250 WORDS)

Background: Vitamin A deficiency (VAD) is endemic in Brazil and health professionals have difficulty in recognizing its subclinical form. In addition, serum retinol concentrations do not always represent vitamin A status in the organism. Objective: To identify VAD in preschool children by the serum 30-day dose-response test ( þ S30DR) and to examine its potential as a tool for the assessment of vitamin A status in the community. Design: A prospective transverse study in which blood samples were obtained from 188 preschool children for the determination of serum retinol concentrations and the children were submitted to ocular inspection and anthropometric measurements. Information about the presence of diarrhea and/or fever during the 15 days preceding the study was also obtained. The children received an oral dose of 200,000 IU vitamin A immediately after the first blood collection. A second blood sample was obtained 30-45 days after supplementation in order to determine the þ S30DR. Results: In all, 74.5% (140/188; 95% confidence interval: 68.3-80.7%) of the children presented þ S30DR values indicative of low hepatic reserves. The mean serum retinol concentration was significantly lower before supplementation (0.92 and 1.65 mmol/l, respectively; Po0.0001). No child presented xerophthalmia; 3.7% (7/188) of the children were malnourished. The presence of fever and/or diarrhea during the 15 days preceding the first blood collection did not affect the þ S30DR value. Conclusions: The prevalence of VAD in the study group was elevated. þ S30DR proved to be a good indicator of subclinical VAD in children from an underdeveloped country. Sponsorship: The study was supported

The effect of an infective episode of chickenpox on the vitamin A status of preschool-aged children was evaluated by use of the relative dose response (RDR) test. Status was determined before and 30, 120, and 180 d after administration of a single oral high-dosage (200,000 IU) supplement of vitamin A. No differences in mean blood levels of retinol or percentage of children showing a positive RDR were apparent until after the infective episode that occurred approximately 90 d after dosing. At 180 d postsupplementation, 74% of children who had been infected tested positive by the RDR, indicative of an inadequate liver reserve of vitamin A, in contrast to only 10% who had not been infected. Paired RDR observations at 0 and 180 d postsupplementation confirmed that the infective episode caused an accelerated depletion of liver reserves of vitamin A.

DVA is a distressing health problem among mothers and newborns and its diagnosis must be included in antenatal care. This reinforces the concept that intervention programs must emphasize changes in feeding practices and focus on the most vulnerable groups, of which pregnant women warrant special attention, regardless of socioeconomic stratum.

Serum vitamin A was determined before and 30-45 d after the administration of6O.6 mg (212 Mmol) vitamin A to 544 Brazilian children residing in slum areas of Recife. The frequency-distribution curves were compared in a subgroup of children whose vitamin A status was assessed initially by the relative-dose-response (RDR) test. The curves of children with negative (adequate status) and positive (inadequate status) RDR tests were different. The difference disappeared after supplementation. The shape of the distribution curve after supplementation was close to normal with a mean, median, and 95% confidence interval of 1.78 ± 0.49, 1.68, and 1.02-2.90 jzmol/ L, respectively. The postsupplementation curve derived from this underprivileged child population may serve as a reference for diagnostic, surveillance, and program-evaluation purposes. AmiClinNutr l99l;54:707-ll.

1. In an attempt to elucidate the pathogenic mechanism of the fatty liver of kwashiorkor some aspects of lipid metabolism were studied in ten patients with kwashiorkor and nine with marasmus, so classified according to the clinical and laboratory findings.2. Plasma lipid levels, especially those of triglycerides, were low in patients with kwashiorkor; they showed a marked rise very early during treatment.3. The changes in the plasma lipid levels occurred mainly in the serum lipoprotein fraction of density < 1.063. The elevation of plasma lipid levels during treatment coincided with a loss of liver lipids and a marked rise in serum protein concentration.4. The findings support the suggestion that the primary mechanism in the production of the fatty liver of kwashiorkor is an impairment in the synthesis of lipoprotein of very low density, probably due to the rate-limiting synthesis of its protein moiety.5. In patients with marasmus no modifications in lipid metabolism were detected by the methods used.

Vitamin A status (umbilical cord retinol levels) of 253 newborns in two public hospitals of Rio de Janeiro showed a high prevalence (55.7%) of deficiency (retinol levels below 1.05 µmol/l). This rate of vitamin A deficiency ( VAD) was independent of other nutritional and an