Administration of vitamin D3 by injection or drinking water alters serum 25-hydroxycholecalciferol concentrations of nursery pigs.

Serum 25-OHD3 concentrations in pigs increased either by vitamin D3 injection or drinking water administration. Although a single vitamin D3 injection enhanced serum 25-OHD3 concentrations greater than water administration in the initial period post-administration, a continuous supply of vitamin D3 via drinking water could maintain higher serum values than the single injection.