Carotenoids and xanthophylls. Canthaxanthin is not genotoxic and it has been reported to inhibit the activity of known mutagens. It shows a low acute oral toxicity in mice (LD50 = 10 g/kg bw). JECFA is unable to assign an ADI because of its association with retinal deposition in humans. Night vision alteration of rabbits occurs after an intravenous injection of 11.4 mg/kg bw. Impairment in vision has also been reported in cats but no effect is observed in rats and mice. Canthaxanthin shows limited absorption in humans.
Rats have shown a partial absorption of apocarotenal. Apocarotenal is converted to β-apo-8′-carotenoic acid and vitamin A. These compounds are accumulated in the liver. Similar behavior has been observed in dogs. Acute toxicity in mice is very low (LD50 > 10 g/kg bw). No adverse effects are observed in male rats provided with up to 500 mg/kg bw for 34 weeks. No adverse effects are observed in dogs fed 1 g/day/14 weeks. In the ethyl and methyl esters of the β-apo-8′-carotenoic acid a very low acute toxicity (LD50 > 10 g/kg bw) is also observed.32