In chronic alcoholics, there is often evidence of nutrient deficiency due to decreased intake, reduced absorption, and impaired utilization of nutrients. The alcoholic has increased nutrient needs due to increased metabolic demands and the need for tissue repair.
Chronic alcohol-related brain damage can often be a direct result of nutrient depletion, especially for the vitamins thiamine, B12, nicotinamide, and pyridoxine. Minor brain damage often goes unrecognized, and by the time a vitamin deficiency syndrome has developed and been diagnosed, irreversible damage often has occurred.
The development of appropriate computerized psychometric tests may allow earlier detection of brain dysfunction associated with malnutrition that can be reversed by nutrient supplementation before permanent damage occurs. Circulating vitamin levels may be a valuable guide to nutritional status, although caution should be exercised in interpreting the results of such tests in the alcoholic.
For thiamine and pyridoxine, for example, there are now methods for accurately determining circulating levels of the active forms of these vitamins that may provide a more direct assessment of vitamin status than earlier methods using indirect measurements, such as red blood cell enzyme activities. On the other hand, in the case of folate and B12, there has been a tendency to opt for the easily performed radioassay techniques, although the earlier microbiological methods actually offer greater sensitivity and probably better accuracy.
Technically difficult assays should not be disregarded if they can provide information that is of greater clinical utility than a simpler assay technique. Clinical laboratories should always keep in mind what their vitamin methods are actually measuring, paying particular attention to whether metabolically inactive forms or analogs are being determined in the assay. This may be important for the interpretation of vitamin data in the alcoholic, who often has difficulty forming active vitamins from their precursors.
Contemp Issues Clin Biochem: Nutrition and Vitamins in Alcoholism
Found at Alkohol adé (german)