Vitamin-D deficiency rickets in Jamaican children

Vitamin-D deficiency is not as rare in Jamaica as previously believed. 9 children with vitamin-D deficiency rickets have been seen at the University Hospital of the West Indies during the past 5 years. All were over 3 years of age at time of presentation. Both dietary deficiency of vitamin-D and lack of exposure to sunlight seem to be important causes. Children living in rural Jamaica seem to be more susceptible to the disease than those living in a city, due perhaps to more prolonged breast feeding and lack of fortified milk feeds on weaning.(AU)

Calcinosis

Two cases of "idiopathic" calcinosis in young boys are reported. One patient received no treatment; in the other, rapid recurrence, followed excision. Both patients are well two and a half years and one and a half years, respectively, after the diagnosis was made and show no evidence of collagen disease. The literature is reviewed (Summary)

Balanced studies in malnourished Jamaican infants. 2. Comparison of absorption and retention of nitrogen and phosphorus from human milk and cow's-milk mixture

A comparison has been made in seventeen malnourished infants of the absorption and retention of nitrogen and phosphorous from human milk, and from cow's-milk mixtures of equal protein, fat and carbohydrate content. N absorption was not significantly different with the two types of milk. On human milk 49 percent of ingested N was retained, compared with 41 percent on the cow's-milk mixtures. This difference was significant. On both types of milk 70 percent of ingested P was absorbed. The P content of human milk is only half that of the cow's-milk mixtures. The percentage retention of P was therefore greater on human milk, but the absolute amounts of P retained were the same on the two milks. It is suggested that although the difference in N retention was not very great, it may be of biological significance to infants living on marginal protein intakes, for whom it is of critical importance to achieve the highest possible efficiency of N utilization (AU)

Balanced studies in malnourished Jamaican infants. 1. Absorption and retention of nitrogen and phosphorus

Nitrogen and phosphorus balances were done on thirty-seven severely malnourished babies, of whom five died. All were treated with either a cow's-milk mixture or human milk. The results have been analysed in relation to the stage of treatment. At all stages of treatment over 80 percent of ingested N was absorbed. The corrected absorption, with allowance for faecal metabolic N, was more than 90 percent, even in the first days after admission to hospital. On N intakes up to 0.5 g/kg/day, more than 50 percent of ingested N was retained. When a correction was applied for endogenous N loss, it was found that N retention progressively fell off as the protein stores were built up. About two-thirds of ingested P were absorbed. Absorption did not vary with the stage of treatment. P retention, like N retention, diminished in the later stages of treatment. In general, more P was retained in relation to N than would be expected from the ratio of these elements in normal muscle. This finding fits in with other evidence of P depletion in these infants. It is suggested that some of the `extra' P retained may have been taken up by bone. In the five babies who died, absorption of both N and P was satisfactory. All the subjects were in positive balance for both N and P at the time of death , which suggest that death was not caused by an irreversible failure of N utilization. Most of the babies who did not die were treated with cow's-milk mixtures that supplied only 0.3-0.4 g N/kg/day. These intakes were lower than those often used for the treatment of protein malnutrition. At this level of protein intake N retention and gain in body-weight both went on at about three times the rate found in normal infant of the same age. It follows that if such intakes are adequate for repair, they should also be adequate for normal growth and maintenance (AU)

The effect of a low-protein diet, and of refeeding, on the composition of liver and muscle in the weanling rat

(1) Fifty-six weanling rats were fed on a low-protein, high-carbohydrate diet designed to simulate that eaten by poor people in Jamaica. After 4 weeks one group was killed and the remainder were rehabilitated on a stock diet containing 18 percent protein. (2) Measurements were made of the protein and deoxyribonucleic-acid content of liver and muscle at the end of the depletion period, at various times during recovery, and also in control animals growing normally. (3) The 'Jamaican' diet caused a virtually complete arrest of growth. Body-weight, liver weight and muscle weight remained constant at the levels reached on weaning. The ratio of nitrogen to DNA was greatly reduced in both liver and muscle. In muscle this reduction occurred entirely at the expense of cellular protein. The connective tissue of muscle continued to increase in amount throughout the depletion period. (4) On refeeding there was a rapid formation of new protein and DNA in the liver, at about twice the rate that obtains during normal growth. In muscle, on the other hand, there was evidence of a lag period before the synthesis of new tissue reached its maximum rate. (5) The bearing of these results on the assessment and treatment of protein malnutrition in human infants is discussed. They tend to support the suggestion previously put forward, that the ratio of non-collagen nitrogen to DNA in muscle may be a useful index of the degree of protein depletion (AU)