High dietary doses of vitamin D (375 million IU/kg) did not affect weight gain or survival of brook trout (Salvelinus fontinalis) over a 40-week period, although red blood cell volume and serum calcium levels increased (Poston, 1969a).
The growth and feed utilization of rainbow trout (Oncorhynchus mykiss) fed diets supplemented with 1 million IU of vitamin D3 for 24 weeks was not affected (Hilton and Ferguson, 1982). Rainbow trout fed diets containing 25,000 and 2.5 million IU of D3 per kg of diet had poorer weight gains and feed efficiency than fish fed 2,500 IU (Vielma et al., 1998).
Juvenile Atlantic salmon (0.16 g or 177 g initial weightview references) fed diets containing 2 million or 1 million IU D3 per kg, respectively, and fed for 120 and 77 days respectively, did not show any toxicity signs (Eide et al., 1998; Horvli et al., 1998).
Channel catfish (Ictalurus punctatus) fed diets containing 50,000 IU of D2 or D3 per kg diet had reduced growth and poor feed efficiencies (Andrews et al., 1980). However, Brown and Robinson (1992) and Lovell and Li (1978) reported no toxic effect up to 1 million IU per kg.
