The combination of 1α,25(OH)2–vitamin D3, calcium and acetylsalicylic acid affects azoxymethane-induced aberrant crypt foci and colorectal tumours in rats

Effects of 1α,25(OH)2–vitamin D3 and acetylsalicylic acid at various dietary levels of calcium (CaCO3) on development of aberrant crypt foci (ACF) and tumours in colon were examined in groups of 16 male F344 rats initiated with azoxymethane and observed for 16 weeks. Calcium was the most potent modulator of ACF development. The total number of ACF increased with low calcium and decreased with high calcium. The number of large ACF decreased with any addition of calcium, acetylsalicylic acid and 1α,25(OH)2–vitamin D3. High levels of calcium alone or in combination with 1α,25(OH)2–vitamin D3 increased the incidence of tumour-bearing animals. 1α,25(OH)2–vitamin D3 and acetylsalicylic acid at 5000 ppm calcium increased the incidence as well.