Nutrition and vitamins in alcoholism.

Chronic alcoholics frequently have evidence of nutritional deficiency due to decreased intake, reduced uptake and impaired utilisation of nutrients. The alcoholic has increased nutrient requirements due to greater metabolic demands and the need for tissue repair. Chronic alcohol-related brain damage can often be a direct result of nutrient depletion, particularly of the vitamins thiamine, B12, nicotinamide and pyridoxine. Lesser degrees of brain damage are frequently unrecognised, and by the time a vitamin deficiency syndrome has developed and been diagnosed, irreversible damage has often occurred. The development of suitable computerised psychometric tests may allow earlier detection of brain malfunction associated with malnutrition, which can be reversed by nutrient repletion before permanent damage occurs. Circulating levels of vitamins can be a valuable guide to nutritional status, although care is needed when interpreting the results of such tests in the alcoholic. Sensitive microbiological and biochemical tests for assessing vitamin status in man have been available for some years, and in addition, new biochemical methods are constantly being developed. It is important that such methods are evaluated, and possibly adapted for clinical use where appropriate. Newer methods may have significant advantages over older, more established techniques. For thiamine and pyridoxine, for example, methods now exist to determine accurately circulating levels of the active forms of these vitamins, which could give more direct assessment of vitamin status than earlier methodology that uses indirect measurements, such as red cell enzyme activities. On the other hand, in the case of folate and B12, there has been a tendency to opt for the easy-to-perform radioassay techniques, when in fact the earlier microbiological methods offer greater sensitivity and probably also better accuracy. Technically difficult assays should not be disregarded if they can give information which is of greater clinical use than a simpler assay technique. Clinical laboratories should always bear in mind what their vitamin methods are actually measuring, particular consideration being given to whether metabolically inactive forms or analogues are determined in the assay. This can be of importance to the interpretation of vitamin data in the alcoholic, who often has problems forming active vitamins from their precursors.(ABSTRACT TRUNCATED AT 400 WORDS)