Transferable drug resistance.

While it may be pedantic to classify partial gastrectomy as a cause of iatrogenic malabsorption, patients who have had this operation must be followed up carefully and for long periods. Loss of weight, anaemia, steatorrhoea and bone changes"0 have been described, and I. D. A. Johnston and his colleagues" showed that if patients with partial gastrectomies can be persuaded to eat sufficient food their weight will increase, while H. S. Hillman" reported weight gain and reduction in steatorrhoea after the administration of pancreatic enzyme. Intestinal malabsorption of fat and vitamin B,, and deficiency of folic acid have been reported during treatment of pulmonary tuberculosis with para-aminosalicylic acid, the malabsorption improving when P.A. S. was withdrawn. " It is of interest to note that impairment of memory was attributed to isoniazid,'4 but these patients were also receiving P.A. S. Liquid paraffin and broad-spectrum antibiotics can interfere with absorption of essential nutriments. Atrophic gastritis is common in the elderly even in the absence of gastrointestinal symptoms. " 16 The consequent reduction in secretion of acid and intrinsic factor results sometimes in impaired absorption of vitamin B,2, and in such cases additional factors such as chronic infection, which increase requirements for vitamin Bl,, or severe dietary deficiency may produce pathological reduction of vitamin B,, in the serum. Borderline levels of serum B,2 are not uncommon in elderly people, but the significance of such findings is not clear. '7 Serum folate is likewise sometimes found to be low in elderly patients admitted to institutions. '8 While none of their patients were elderly, C. E. Denton and R. Smith,'9 in a study of nutritional osteomalacia, conclude that this illness in adults is mainly due to dietary lack of vitamin D and will develop when the diet contains less than about 70 units of vitamin D per day. The usual history is of avoidance of fatty foods or of being a strict vegetarian. To the general practitioner the problem of nutrition of the elderly appears complex. There may exist a high-risk group of people over 65 (advancing age makes little difference) who spend, for various reasons, less than they should on food. Some are depressed and apathetic, perhaps recently bereaved; some have the constant fear of ultimate poverty; others are mildly confused; and a few have esoteric food habits. There is also a group who are immobile because of physical disease and who depend on others for their food; those who require prolonged analgesic therapy, especially with aspirin, should be included. Some older people will come to the doctor complaining of lassitude, apathy, and weakness, and these symptoms call for further investigation. Apart from obvious anaemia, such a syndrome may indicate sideropenia, potassium deficiency, and perhaps deficiency of vitamin C, vitamin B12, or folate. Unfortunately such symptoms in the elderly are non-specific and may also be a manifestation of incipient cerebrovascular disease, intercurrent acute infection, or depression. There are, however, clear indications for giving dietary advice and vitamin supplements to any older person who has recently had a febrile illness, undergone a surgical operation, or sustained injury.