MEET THE VITAMINS

Otago Daily Times, Issue 26197, 6 July 1946, Page 8

MEET THE VITAMINS

NUTRITION RESEARCH A FAMILY THAT REALLY EXISTS By the number of people who shrug their shoulders sceptically, and generally express mild disbelief, it would appear that a comparatively large section of the general public is inclined to doubt that vitamins really exist. They have heard a great deal about the vitmin family and what they will do to maintain or improve bodily health and happiness, but there are many who choose to think of vitamins as imaginary little people invented to persuade the nation to eat the right kinds of food in the right kind of way. But they really do exist, and in tangible form. In fact, an Otago Daily Times reporter who visited the Nutrition Research Department at the Medical School was shown a whole drawerful of members of the vitamin family a collection that is worth several hundred pounds. All were housed in squat little bottles and all were carefully labelled. They were not at all exciting to look at. In fact, they looked no more interesting or exciting than baking powder or sulphur according to which branch of the family they belonged. But the array proved that vitamins exist in tangible form and that they have been isolated and controlled by the scientist. After such a glimpse at so much potential health, vigour, energy and what-have-you, it was but a small step to inquiring more about vitamins and the people who worked with them. In charge of the Nutrition Research Department in Dunedin is Dr Muriel Bell, and with her are four young research workers engaged in keeping the vitamin youngsters carefully taped. Tintometers and Rats The first of the quartette seen at work by the reporter was showing close interest in vitamins A and D, both of which are found in several fish liver oils. Vitamin A is the one that builds up in the body resistance to infection by strengthening the lining membranes of the nose, throat and lungs. It also helps to keep the skin healthy and is very beneficial to expectant mothers. Vitamin D, without being technical, is the vitamin produced when sunlight falls on the skin and is necessary to prevent rickets and to grow good teeth in young children. The amount of vitamin A is measured by means of a tintometer, which, as the name suggests, has to do with colours. A small sample of an oil, liquid, or an extract of a solid (such as carrots) which has been dissolved in chloroform is placed in a tray in the tintometer. Its colour is quickly matched with a tint that is produced by means of colour controls. As soon as the artificially-produced colour exactly matches the sample, a scale is read which gives the amount of vitamin A contained in the tray. It is then only a matter of arithmetic to ascertain the amount of the vitamin in the substance being tested. Tests by means of the tintometer can be done by a competent research worker in a few minutes compared with the three months or so that was necessary in the past when rats were used. The same research worker tests for vitamin D by means of white rats, of which she is very proud, and in which she takes a great interest. She handles the rats without any feminine fears or distaste, and enjoys showing one over her rat farm. Many of the rats have litters of 15 or only slightly fewer. Incidentally, the same research worker does not like mice, and her room-mate has to deal with any such intruders. There are scores of rats of various ages and sizes in the warm, thermos-tatically-controlled room. Seven groups each of seven rats are used for the vitamin D test. The rats are first given a diet deficient in this vitamin, and then, after a period, are dosed with oils containing varying amounts of vitamin D. At the end of a month the rats are examined and the amount of vitamin D absorbed in that time is ascertained by the amount of calcium and other salts contained in the bones. The Vitamin B Twins The vitamin B twins, B 1 and 82. are different in appearance, the former white and the latter having a jaundiced coiour approaching that of sulphur. These vitamins are the ones that enable the body to make use of 'the fuel provided by the foods consumed. The research worker who was testing for vitamin B 1 was ascertaining the amount contained in a fine specimen of Auckland snapper. She cut a juicy fillet so that it contained samples of the fish from head to tail. After carefully weighing it, she placed it with ’ a known weight of water into an electrically-operated blender which turned the fish and the' water into a whitish-grey paste. This substance is then placed in an incubator for 16 hours, during which time the vitamins are extracted by means of digests—a process that is somewhat similar to that which takes place in the human stomach. A compound formed from the vitamins is placed in a fluorimeter where, in an ultra-violet light, it gives off a violet fluorescence. The amount of fluorescence recorded is compared with a given standard and this gives the amount of vitamin B 1 in the sample. This chemist also ascertains the amount of vitamin destroyed in cooking and the effect of storing on the vitamin content of a substance.

Vitamin B2 is the pet of another research worker. The amount of B2 is tested by two means—chemically and micro-biologically. This vitamin is the jaundiced member of the family and, unlike the violet fluorescence of 81, it has a yellowish-green fluorescence when placed in an ultra-violet light. It is also placed in a fluorimeter and the amount of fluorescence is again proportionate to the amount of B2 present. Exclusion of Light In the micro-biological method, bacteria are added to a medium containing vitamin 82, or riboflavin to give it its other name, and the growth of bacteria is proportionate to the amount of B2 in the medium. Incidentally, B2 tests have to be done in the dark for light affects the vitamin, which shows that food containing it should be kept in dark places. For example, milk, of which a pint contributes half our daily requirement, should not be left out in the light Last to come under the notice’ of the reporter was vitamin C, the wellknown member of the family that‘is contained in green vegetables and certain fruits. It is tested by chemical means—in solutions in test tubes and in comparatively quick time. It can be seen, therefore, that the vitamin family really exists and is intimately known by the Nutrition Research Department, which is carrying out important research into questions affecting the diet and general health of New Zealanders.