Table 4.

Results of studies in animal models with Cd exposure and vitamin A treatment and relationship between Cd exposure and vitamin A in blood concentration in human studies, collected on PubMed in May 2021

Reference	Research model	Study description	Main results
55	Rats, Sprague Dawley	–CG – CdCl2 (2.5 – 4.0 mg/kg b.w. single injection) –G1 – CdCl2 (2.5 – 4.0 mg/kg b.w. single injection) and vitamin A (75 mg/kg/day by oral gavage for 7 days pretreatment) –CG – CdCl2 (2 mg/kg b.w. single injection) –G1 - CdCl2 (2 mg/kg b.w. single injection) and vitamin A (75 mg/kg/day by oral gavage for 7 days pretreatment)	–plasma: ALT↓ –kidney: histopathological changes↓ –testis: damage within germinal epithelium↓ –lungs: inflammatory response↓ –liver: MT↑Cd↑ –kidney: MT↔, Cd↔ –lung: MT↔, Cd↓ –testis: MT↔, Cd↓ –pancreas: MT↑
56	Rats, Wistar	–CG – CdCl2 (1 mg Cd/kg b.w./day for 21 days) –G1 – CdCl2 (1 mg Cd/kg b.w./day for 21 days) and vitamin A (500 lU/kg b.w./day for 21 days simultaneous) –G2 – CdCl2 (1 mg Cd/kg b.w./day for 21 days) and vitamin A (500 lU/kg b.w./day for 21 days post-treatment)	Gl, G2 vs. CG –serum: AST↓,ALT↓, ACP↓, ALP↓ –liver: AST↓, ALT↓, ACP↓, ALP↓, –heart: AST↓, ALT↓, ACP↓, ALP↓ –behavioral effects: SMA↑, REf↑
57	Rats, Wistar	–CG (N = 7) – deionized water for 1 month –G1 (N = 7) – Cd (100 ppm in drinking water for 1 month)	G1 vs. CG –rats: body weight↓ –eyes: weight↑, TBARS↑, vitamin A↓
58	Women, 54-64 years, Sweden	–G1 – women with high serum retinol and low urinary Cd	in Gl: –BMD↑
37	People, ≥20 years	–G1 (N = 7826)	in Gl: –blood: cadmium with leukocyte telomere length – inverse association –serum: vitamin A with leukocyte telomere length – positive association

ACP – acid phosphatase; BMD – bone mineral density; MT – metallothionein; RRE – rota-rod endurance time; SMA – spontaneous motor activity.

Other abbreviations as in Table 1.