HOME SCIENCE

Evening Star, Issue 21810, 28 August 1934, Page 9

HOME SCIENCE

ASSOCIATION OF ALUMNAE CONFERENCE CONTINUED TLe conference convened by the Association of Home Science Alumn® was continued in the Home Science ment of the Otago University this morning, the large gathering of delegates hearing a series of instructive addresses. ULTRA-VIOLET RAYS. Some points in the value of ultraviolet rays were touched _on by Dr Elizabeth Gregory, who /aid 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 (1) sunlight, and (2) ultra-violet rays, artificially produced. As the vitamin D seemed to act primarily by mobilising the calcium and .phosphate supply brought to the bone )by the blood serum, these factors were 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 and phosphorus content of the blood serum 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 D appeared to aid in increasing the absorption of calcium and'phosphorus by rendering the reaction in the intestine more acid.

The ultra-violet rays, effective in forming 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 environments 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 cjimates 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 and a-half pints daily for children. From experience it had been found very difficult to supply 1 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 m cream and there was some in fruits and vegetables. INFANT FEEDING. Speaking on child diet, Dr Gregory dealt largely with the use of milk, pointing out fundamental differences between human milk and cow’s milk. She said _ that, although there was less protein in _ human milk, it had a higher biological value than cow’s milk. Human milk, moreover, had more iron, and altogether, despite its having less protein, its energy value was the same. Dr Gregory went on to outline various features of the different systems—Plunkct, Marriot (American), and Paterson and Smith (English). The English and American systems, she said, were practically the same. USES OF MILK. A striking demonstration of the manifold uses to which milk can be put was given by Miss Stenhouse, who, in an amazingly short time, made a variety of delicacies, which, if one could judge by appearance, should certainly make an appeal to old and young alike and which undoubtedly should be assimilated with appreciation' even by those who normally have little liking for this valuable food.