Dennis E. Carey

Achievement of in utero retention of calcium and phosphorus accompanied by high calcium excretion in very low birth weight infants fed a fortified formula

Calcium and phosphorus retention was evaluated in 13 very low birth weight infants who were fed an experimental formula designed to deliver quantities of calcium and phosphorus sufficient to meet the intrauterine accretion rates for these minerals. Retention of calcium and phosphorus in slight excess of these rates was achieved without any apparent difficulties for the infants. Biochemical measurements demonstrated normal serum calcium (9.8 +/- 8 mg/dL) and alkaline phosphatase (242 +/- 51.6 IU) values. However, there was evidence of high tubular reabsorption of phosphate (98.1% +/- 3.3%), hypercalciuria (7.2 +/- 3.8 mg/kg/d), and a relatively low serum phosphorus concentration (5.7 +/- 0.6 mg/dL). This biochemical picture is similar to that seen in phosphorus deficiency except for the low alkaline phosphatase activity. The latter finding, in concert with the high retention of calcium and phosphorus in these balance studies, makes such a diagnosis unlikely. We speculate that this biochemical picture is the result of an inappropriately high calcium/phosphorus ratio.

Phosphorus Deficiency Syndrome in Very Low Birth Weight Infants

Inadequate dietary phosphorus intake is a contributing factor to the occurrence of metabolic bone disease in very low birth weight infants. This article reviews the clinical presentation and the pathophysiology of the phosphorus deficiency syndrome in premature infants. Recommendations for therapy and prevention of phosphorus deficiency are presented.

Yogurt Contributory Factor in Development of Nutritional Rickets

Vitamin D deficient rickets occurred in a 15-month-old black girl for whom yogurt had been substituted for milk products. Investigation determined that commercially available yogurt contains no vitamin D, and that this fact is not generally recognized by lay persons and health professionals. Use of yogurt as a major source of nutritional intake in infants and young children may be a contributory factor in development of vitamin D deficiency rickets.Vitamin D deficient rickets occurred in a 15-month-old black girl for whom yogurt had been substituted for milk products. Investigation determined that commercially available yogurt contains no vitamin D, and that this fact is not generally recognized by lay persons and health professionals. Use of yogurt as a major source of nutritional intake in infants and young children may be a contributory factor in development of vitamin D deficiency rickets.

PROCOLLAGEN–BIOCHEMICAL MARKER OF GROWTH IN ENTERALLY FED VLBW INFANTS

12 AGA 28-32 week gestation infants were studied during the first 2-3 mos. of life to determine the effect of feeding premature human milk (HM), fortified premature human milk (FHM) and Similac Special Care (SSC) on growth and bone mineralization. Alkaline phosphatase (AP), tubular reabsorption of phosphate (TRP), urinary calcium excretion (uCa), serum phosphorus (P), and type I procollagen (PC) were measured. Mean results:Poor wt gain in the HM gp was associated with a significantly lower PC. The FHM gp grew as well and had similar PC levels as the SSC gp but like the HM gp exhibited biochemical evidence of phosphorus deficiency and inadequate bone mineralization: decreased P and increased AP, TRP and uCa. The data suggest that current special formulae designed for VLBW infants promote better growth and mineralization than HM or FHM and PC may prove a useful marker of optimal growth response.