HOME SCIENCE

Otago Daily Times, Issue 22353, 29 August 1934, Page 5

HOME SCIENCE

CONFERENCE OF ALUMN/E YESTERDAY’S PROCEEDINGS The delegates to the conference of .alumnae of the Association of Homo Science had a full day’s work yesterday. In the morning two addresses were given by Dr Elizabeth Gregory, ami a demonstration in'the uses of milk in the preparation of food was presented by Miss Stenhouse.' The mid-day period was devoted to discussion groups, and in the afternoon a demonstration of dressform and drapery was given by Miss Bowbyes, while informal talks were delivered to groups in the. evening. ADDRESS BY DR GREGORY. Some points in the value of ultraviolet rays ■ were touched on by Dr Elizabeth Gregory, who said that calcium, phosphorus, and vitamin D were three factors that had a very important relationship to the. incidence of, rickets. The vitamin D might be ingested or formed in the body by irradiation by (I) sunlight, and (2) ultra-violet rays, artificially produced. > As the vitamin D seemed to ict primarily by mobilising the calcium and phosphate supply brought to the bone by the blood serum, these factors wer a interdependent. Thus the bodily requirement for „ vitamin D varied inversely with the adequacy of the mineral content of the diet. Rickets was a condition in which mineral metabolism was disturbed in such a way that calcification did not take place normally. There were three types: (1) Low phosphorus rickets, where the ■ phosphorus content of the blood serum was reduced, the calcium content remaining normal, most frequently clinically. (2) Low calcium rickets, where the calcium content of the blood serum was reduced, the phosphorus content remaining normal. (3) Low calcium .rickets, where the phosphorus content of the blood scrum was reduced. The subnormal amounts in the blood were not necessarily due to insufficient amounts in food, but might be due to perverted utilisation. Vitamin P appeared to aid in increasing the absorp tipn of calcium and phosphorus by rendering the reaction in the intestine more acid, The ultra-violet rays, effective in vforming vitamin D, did not appreciably pass through window glass. They were also very largely absorbed in passing 'through the - atmosphere, especially if cloudy or smoky. Therefore, clear weather, high altitudes, and the sun high in the heavens were all favourable conditions. Water and snow were good reflectors; therefore snowfields and high , mountains in clear weather were eu vironments particularly rich in ultraviolet rays. At the seashore there was an extra amount of ultra-violet rays..

The pigment in coloured races was produced" as a protection against too much ultra-violet rays, and therefore coloured peoples in temperate climates were particularly susceptible to .rickets'. The requirements for a man weighing eleven stone were .68 grams of calcium and 1.32 grams of phosphorus daily, and for a child 1 gram of calcium and 1 gram of phosphorus daily. Whether the requirement was supplied in the diet depended almost entirely on the amount of milk present. The optimal amounts of milk suggested were one pint daily for adults and one pint and a-half daily for children. From experience ft had been found very difficult to supply, one gram of calcium daily in a -child’s dietary, unless at least one pint of milk was ingested. The best sources of. calcium and phosphorus were milk and cheese. These substances were practically negligible in butter, but there was a little in. cream and there was some in fruits and vegetables.. ; ] FEEDING OF INFANTS, ; .In the course of an address on new ) methods of infant feeding, Dr Gregory explained the fundamental differenced between human milk and cow's milk. Although there was much less’ protein in human milk; ,it had a higher biological value, and consequently less of it was required. In addition to this, human milk contained more iron, and actually the energy value of human milk and cow’s milk was . the same. The remainder of. .Dr Gregory’s address was devoted to an explanation of the composition of- the Plunket system and ..of the systems of Marjott, an American, and Paterson and {Smith, of England. • The English and -American systems'were, .she commented, practically the same. ■ : f USES. OF MILK. Following the addresses by Dr Gregory, Miss Stenhouse gave an interesting demonstration of the manner in which milk might be; used to .greater, advantage in the preparation of foods. In this the importance" of making the food attractive in appearance as well as in its appeal to. the palate was stressed, and the variety of ways in which milk could be so utilised was shown by the number of dishes which were displayed.