The possible role of vitamin K deficiency in the pathogenesis of Alzheimer's disease and in augmenting brain damage associated with cardiovascular disease

The incidence of Alzheimer's disease (AD) increases with age and in carrier s of the apolipoprotein E4 genotype. A relative deficiency of vitamin K, af fecting the extrahepatic functions of the vitamin, is common in ageing men and women. The concentration of vitamin K is lower in the circulating blood of APOE4 carriers than in that of persons with other APOE genotypes. Evide nce is accumulating that vitamin K has important functions in the brain, in cluding the regulation of sulfotransferase activity and the activity of a g rowth factor/tyrosine kinase receptor (Gas 6/Axl). The hypothesis is now pr oposed that vitamin K deficiency contributes to the pathogenesis of AD and that vitamin K supplementation may have a beneficial effect in preventing o r treating the disease. Vitamin K may also reduce neuronal damage associate d with cardiovascular disease. (C) 2001 Harcourt Publishers Ltd.