Seasonal and geographical variations in the growth rate of infants in China receiving increasing dosages of vitamin D supplements.

In theory, sunshine exposure is sufficient to maintain normal vitamin D concentrations for the optimal growth of newborn infants. To determine whether season of birth, latitude (north v. south) and increasing dosages of vitamin D supplements would influence the growth rate for the first 6 months of life, 255 healthy fall-and spring-born infants from two northern and two southern cities in China were randomly assigned to receive either 100, 200, or 400 IU of vitamin D a day. The study showed that season of birth and dose of vitamin D did not affect the growth rate of infants born in the same latitude, but a significant difference was found in the gain in length over the 6-month period between infants from the north and infants from the south (P = 0.0001). Regional differences among the Chinese people, other than sunshine exposure, may have influenced the difference in length gain.

Nutritional efficacy of a fortified weaning rusk in a rural area near Beijing.

A micronutrient-fortified rusk for weanling children was tested in a rural area near Beijing. Two hundred twenty-six children aged 6-13 mo were randomly assigned by village to either a micronutrient-fortified or an unfortified rusk, daily for 3 mo. The fortified rusk contained extra zinc; iron; calcium; vitamins A, D, and B-12; thiamin, riboflavin, niacin, and folic acid. Infants receiving the fortified rusk exhibited no decline in hemoglobin concentrations during the study whereas those receiving the unfortified rusk exhibited a significant decline. Improvements were also seen in erythrocyte porphyrin, plasma vitamin A, and riboflavin status, but these improvements were seen in both of the groups. Micronutrient fortification was probably beneficial for iron status and the fortified rusk promises to be an effective vehicle for supplementation.

PIP: In February-June 1990, in China, researchers assigned, by village, 226 6-13 month old, full-term, healthy infants from 33 villages of the Mi-yun rural area near Beijing to receive daily either a micronutrient-fortified or an unfortified rusk for 3 months. 15% of all infants were initially anemic, but not severely so. Extra zinc; iron; calcium; vitamins A, D, and B-12; thiamin; riboflavin; niacin; and folic acid fortified the rusk. The study aimed to determine the efficacy of the micronutrient fortification. Mean hemoglobin levels decreased considerably in the infants in the unfortified rusk group (12.85 g/L vs. 12.95 g/L; p .01), but remained the same for the fortified rusk group. The change in the unfortified rusk group's hemoglobin levels was much greater than that of the fortified rusk group (p .01). The significance of the supplement-group effect fell when the researchers included initial ferritin and free erythrocyte porphyrin concentrations (p = .04-.08). There was a considerable reduction in free erythrocyte porphyrin in both groups of infants (p .001) and the response was basically the same for both groups. Even though the fortified rusk group experienced a significant increase in plasma vitamin A (.093 mcmol/L; p .01), the difference in response between the 2 groups was not significant. Infants in the fortified rusk group experienced a considerable fall in vitamin E levels (p .001) which was a significantly greater decline than that observed in the unfortified rusk group (2.6 mcmol/L vs. .79 mcmol/L; p = .012). The erythrocyte glutathione reductase index of riboflavin status improved significantly in the fortified rusk group (.07; p = .05), but it was not significantly different from that of the unfortified group. These results suggested that fortifying a commercial weaning risk with micronutrients benefited the iron status of these children.

Studies on iron deficiency anemia, rickets and zinc deficiency and their prevention among Chinese preschool children.

The incidence of iron deficiency anemia, rickets, and zinc deficiency is very high in Chinese preschool children and a method for prevention is urgently needed. From our studies, it can be seen that a soft drink powder is a convenient vehicle for the supplementation of iron, zinc, calcium, vitamin D, riboflavin, and ascorbic acid. Table salt is also a good, low-cost carrier for iron and zinc, and cow's milk can only be used for the enrichment of vitamins A and D. In our study the therapeutic dose of iron was lower than 3 mg/kg body weight recommended by the WHO Expert Committee. As ascorbic acid can enhance the absorption of iron in the body, so 300 mg vitamin C was added to 100 g of soft drink powder containing 100 mg of elemental iron. Ten g of powder is not only enough for the prevention of iron deficiency anemia but it can also cure iron deficiency anemia within 3 months. One hundred mg of iron in 100 g of table salt is an adequate level, because an adult or a child taking 10 or 5 g of salt will receive 10 and 5 mg of elemental iron respectively. This dosage is adequate for the prevention of anemia. From our results, 10 mg of zinc daily is enough for the prevention and treatment of zinc deficiency in preschool children. Four hundred IU of vitamin D (from fortified soft drink powder or enriched fresh cow's milk) orally-administered daily, is a good way to prevent rickets in infants and young children.

Prospective study of vitamin D supplementation and rickets in China.

To determine whether amounts of vitamin D lower than recommended doses are effective in preventing rickets, 256 term infants from two northern and two southern cities in China were studied in a randomized trial of vitamin D supplementation (100, 200, or 400 IU/day) during the first 6 months of life. Cord blood and 6-month blood samples were collected and radiographs were obtained at 3 to 5 days and at 6 months of age. Cord serum 25-hydroxyvitamin D concentrations were lower in the north than in the south (5 vs 14 ng/ml (12.5 vs 35.0 nmol/L); p less than 0.01). Wrist ossification centers were less likely to be present at birth in the northern children than in the southern children (p = 0.009) and were more likely to be present in infants born in the fall who had higher cord serum concentrations of 25-hydroxyvitamin D (p = 0.04). Serum 25-hydroxyvitamin D concentrations were lower in northern children 6 months of age than in southern children (p = 0.005) and were higher with an increasing supplemental dosage of vitamin D (p less than 0.001), particularly in infants in the north. None of the infants had rickets at 6 months of age. Because of the low serum 25-hydroxyvitamin D concentrations, especially among infants in the north, it may be prudent to supplement the diet with vitamin D at a dose of 400 IU/day.

[The trace element zinc and aphthosis. The determination of plasma zinc and the treatment of aphthosis with zinc]. / Le zinc, oligo-élément et l'aphtose. Le dosage du zinc plasmatique et le traitement de l'aphtose par le zinc.

Content of Zn and Cu in blood and hair and comparative levels of Zn and Cu in blood were determined in 83 patients with aphtosis. Internal and external treatment with Zn preparations in 159 patients with aphtosis produced good results in 81.13% of cases, as evaluated at 1-year follow up review.

Low levels of zinc in hair and blood, pica, anorexia, and poor growth in Chinese preschool children.

Zinc concentrations in plasma and hair were measured in 703 children, aged between 1 and 6 yr, and correlated with parameters of physical development. In the first group of 187 children brought to the Child Health Clinic for routine observation there was a positive correlation of hair zinc content and height for age, with an increased prevalence of low hair zinc content in children of shorter stature. A second group of 303 children in nurseries and kindergartens in Beijing exhibited a hair zinc content of 92 micrograms/g, and 34% of these had very low zinc values below 70 micrograms/g. The third group consisted of 213 children who were brought into the outpatient clinic for a variety of complaints, including pica, anorexia, and poor growth; these had significantly lower values of zinc in hair and plasma than well-nourished children and responded to zinc supplementation with improvement of growth and the disappearance of pica and anorexia. These results suggest that the diet consumed by the population studied may be marginal or inadequate in its content of available zinc.