Vitamin D Levels in Bone Gold 

A recent research paper produced by the Hong Kong Jockey Club addresses the 1978 NRC Equine Feeding guidelines. The research showed that previous guidelines were obsolete and needed to be revised with daily intakes radically requiring an increase.

The 1978 NRC supplementation levels were erroneously based on injectable dose rates and serum Vit D levels were not measured.

The recent research validates the Bone Gold recommended feed rate as being correct.

Note the following quotation:

It should be noted that the NRC recommendations were extrapolated from an in vivo experimental study conducted in 1979 [31] where circulating vitamin D metabolites were not measured. In light of more recent advances in equine research, up to date and evidence based guidelines are much needed to better inform daily dietary requirements for vitamin D for sedentary and athletic horses.