P. C. Jeans

The effect of vitamin D on linear growth in infancy: II. The effect of intakes above 1,800 U.S.P. units daily

Summary The rate of linear growth of nine infants given from 1,800 to 4,600 units of vitamin D daily has been compared with standard rates of growth, and with the growth of infants given the same dietary regimen but amounts of vitamin D varying from 135 to 340 units daily. The rates of growth with the very high vitamin D intake were similar to or less than those of infants given 135 units daily, and definitely lower than the growth rates of infants given 340 units of vitamin D daily. It is concluded that the effect of vitamin D on increasing linear growth reaches a maximum when the vitamin D intake is greater than 135 and less than 1,800 units, probably in the neighborhood of 340 to 600 units daily. Vitamin A in amounts exceeding those of the food (milk, vegetable, and fruit purees) apparently does not affect linear growth of infants. Factors affecting growth rates of individual infants are discussed. It is concluded that in order to determine the effect of the dietary regimen, growth should be studied well past 6 months of age, preferably during the greater part of infancy. Growth during the first 8 weeks of life may be affected by factors other than the dietary regimen of the infant.

The effect of vitamin D on linear growth in infancy.

Summary The rate of growth in length of infants given one teaspoonful of high grade cod liver oil (340 to 400 U.S.P. units of vitamin D daily) has been compared with the rate of linear growth of infants given the same type of diet, but with the source of vitamin D from irradiated milk (60 to 135 U.S.P. units of vitamin D daily) or its vitamin D equivalent as cod liver oil or cod liver oil concentrate milk, and with standard growth rates reported in the literature. A review of the growth standards shows that the rate of linear growthin infancy is increasing. Standards reported in 1929 and 1933 show rates of growth definitely increased over those of older standards. Infants given 340 to 400 U.S.P. units of vitamin D daily grow at rates definitely more rapid than those of even the recent standards. Infants ingesting from 60 to 135 U.S.P. units of vitamin D daily grow at the same rate as the recent standards. Exposure to sunlight increased the rate of growth in the few infants in whom this measure was tried and who were receiving the lower of the two stated amounts of vitamin D. The increased rate of linear growth is ascribed chiefly to the increased intake of vitamin D and its resultant effect on skeletal growth. Although the influence of vitamin A has not been entirely excluded, certain of the observations recorded indicate that vitamin A was not the limiting factor in the growth of the infants studied.

Dark adaptation and vitamin A

Summary Further observations on dark adaptation as determined by means of the biophotometer are reported. Evidence is presented that the results obtained with this instrument are consistent from test to test of the same subjects and correspond with the vitamin A status of those subjects, when the technique employed is satisfactory and when certain interpretations are applied. By mathematical analysis of the results, the technique described in 1937 has been shown to be satisfactory. Reports of inconsistent results by other observers have been reinterpreted in the light of our own experience, with the conclusion that the apparent inconsistencies have a logical explanation in variability of the status of the subject rather than in fallibility of the test. Normal subjects with ample vitamin A intake, while remaining ingood health, have normal test results at all times. The subjects of our observation group who had poor dark adaptation and who submitted to therapy attained normal adaptation in all instances while receiving vitamin A. Three subjects receiving an experimental diet of low vitamin A content showed changes in dark adaptation ability paralleling the depletion of this material and later repletion. In the geographic region in which these observations were made,dietary deficiency alone seemed to be the cause of impaired dark adaptation in few instances. The most frequent and usual cause of impaired adaptation seemed to be a utilization deficiency resulting from illness, especially illness resulting from infection. A seasonal incidence of dysadaptation was observed. The greatest number of instances was found in the winter and the smallest number in the summer. It is believed that the seasonal incidence is related more closely to the seasonal occurrence of infections than to seasonal variations in diet. In the case of an orphanage in which the children were receiving approximately 2,000 units of vitamin A in the diet daily, no instances of abnormal dark adaptation were observed during a winter period of observation. In a group of 120 school children, 5 per cent had dark adaptationnot wholly normal in the fall. In the winter almost 20 per cent had abnormal adaptation. In the spring only one child of fifty tested had an abnormal test result, and this one child gave a borderline test.

Utilization of Calcium Salts by Children

Children 4-12 years of age have been given calcium salts in amounts such that the calcium content was equivalent to that in a pint or quart of milk. The retentions of calcium and phosphorus have been determined and compared with the retentions from the equivalent quantities of milk. The calcium and phosphorus retentions of children from 1 to 4 years of age have been determined when a quart of milk was given as the chief source of calcium, and when a calcium salt was substituted for one pint of the milk. A few studies were made wherein the salt was substituted for all of the milk. The protein intake of each diet was kept approximately constant during the salt and milk periods. The salts used were calcium lactate, carbonate, gluconate, and the di- and tri-phosphates. The latter was given either as the salt or in the form of a purified bone meal. No difference was observed in the relative retentions from the two sources. The results are summarized in Table I. In general, the calcium and phosphorus retentions when the calcium phosphates were fed, were approximately equal to those from equivalent quantities of milk. The very high retentions observed when these salts were fed after periods of low calcium intake indicate that all forms used are well absorbed by the average child of these ages. The retentions with the other calcium salts, the gluconate, lactate and the one study with calcium carbonate, are not so consistent as those obtained with the calcium phosphates. A greater individual variation was observed in the quantity of calcium and phosphorus retained by the different children. In general, it appeared that when the intake levels of calcium and phosphorus were approximately equal, the retentions of both these elements were good in relation to the intake, but that the greater the difference between the intake levels of calcium and phosphorus, the less satisfactory were the relative retentions of these elements.

Effectiveness of vitamin D in infancy in relation to the vitamin source.

This report concerns the preliminary findings regarding the utilization by the human infant of vitamin D from different sources. The criterion chosen was the quantity of calcium retained by well infants given the same amount of milk and the same rat unitage of vitamin D. Irradiated evaporated milk containing 50 units,∗ and evaporated milk containing the unsaponifiable fraction of cod liver oil (Zucker concentrate) allowing 150 units per quart of reconstituted milk respectively, were compared with evaporated milk plus vitamin D given separately as a cod liver oil containing 40 units of D per gram. The Zucker concentrate milk was mixed with plain evaporated milk, and the quantities of cod liver oil were so chosen that the vitamin D unitage of each diet was constant for any given intake of milk, and was regulated by the amount present in the irradiated milk. The youngest infants received only 22 units daily, but by 16 weeks of age, all the infants were ingesting approximately 50 units of D daily. The plan of study was to give each of the 3 experimental diets to a group of infants of the same age and milk intake; after a period of about 6 weeks, the diets were changed so that each infant received each diet in turn. At the beginning of the study, 3 infants were from 5 to 8 weeks of age; 3 from 16 to 24 weeks; and one infant a year old was given each diet in turn. The relations observed between calcium intake and retention per kilogram body weight are shown in the chart. The source of vitamin D used in each experiment is indicated by the different symbols. The line shows the average curve of retention :intake obtained from over 200 experiments upon infants having the same age range and milk intakes, but given approximately 125 units of vitamin D daily in the form of cod liver oil.

Retention of calcium by infants fed evaporated milk containing cod liver oil concentrate.

This report concerns the quantities of calcium retained and the growth in length and weight of 5 white infants fed evaporated milk containing the unsaponifiable fraction of cod liver oil (Zucker concentrate) in an amount which allowed 400 U.S.P. units of vitamin D to the reconstituted quart. When the experiment was started one infant was 11 weeks, one 6 weeks, and the remaining 3 infants 10 to 20 days of age. The vitamin D intake of the youngest infants was 245 units daily; the maximum intake was 400 units a day. The intakes and retentions of calcium per kilogram of body weight are plotted on the chart. For comparison are shown average values from former observations. The solid line shows the average calcium retentions of infants given 340 U.S.P. units of vitamin D daily as cod liver oil and represents 200 periods of study of 24 infants; the dotted line shows the average retentions from 135 U.S.P. unit milk (60 to 135 units daily) as determined from 40 periods of study of 7 infants. The quantities of calcium retained from any given intake of the 400 unit milk were within the range observed in infants to whom 340 units of vitamin D as cod liver oil were given daily, and the average values for each intake range is approximately the same as that of the large control group, but about 10 mg. per kilo higher than the average retentions observed when 135 unit milk was given a similar group of infants. 1 The serum calcium values varied from 10.4 to 12 and the serum phosphorus from 5.7 to 7.2 mg. per 100 cc.; the average values were 11.0 and 6.3 mg. per 100 cc., respectively. The rate of growth of each infant, both in length and weight, was above the Kornfeld 2 average, and equal to the average rate of growth of the infants given 340 units of vitamin D daily. No infant developed rickets; dentition was early and muscular development excellent. It is concluded that milk containing cod liver oil concentrate (Zucker) sufficient to allow 400 U.S.P. units of vitamin D to the reconstituted quart, allows high retentions of calcium, prevents the development of rickets, and permits excellent growth and development of the infants.

Diet in malnutrition and celiac disease: With special reference to the use of dextrose and bananas

Summary Four types of diets were used in a study of weight gain in undernourishedchildren, viz., the customary diet used in this hospital, designated the “normal” diet, a diet richer in fat called the “fat” diet, and a diet low in both fat and complex carbohydrates, containing its calories as protein and dextrose, the “dextrose” diet. In the fourth diet ripe bananas were substituted for an equivalent amount of dextrose. Weight gains were more rapid with the dextrose and banana dietsthan with either of the other two. Consistent weight gains were obtained with the dextrose and banana diets at lower caloric intake than with the other diets. The fat diet necessitated largest caloric intake in order to maintain consistent weight gain. The rapid early gains in weight observed with banana and dextrosediets, presumably due in large part to water retention, were not subsequently lost, but were apparently replaced by tissue gains without an intervening period of slow or no gain. The psychologic effect of such gains is apparent. The studies of retention of calcium, phosphorus, and nitrogen confirmthe results of the studies of the weight gain and show that diets made up of protein and simple carbohydrates provide intake levels of these substances such that good body tissue can be built rapidly. These studies provide proof that the spectacular weight gains observed are due primarily to sound tissue growth, and that the resulting normal weight is an indication of normal body composition and not due to inordinate amounts of fat or water.