The effects of reduced dietary phosphate intake on plasma osteocalcin levels in sheep.

Six sheep were fed a diet with normal phosphorus content for 1 month after which plasma inorganic phosphorus (Pi), calcium, osteocalcin (BGP) and alkaline phosphatase concentrations were measured over a 48 h period. The same animals were then fed a low phosphorus diet for a further month prior to a second sampling period. Plasma Pi and BGP concentrations were significantly reduced after the low phosphorus diet; there was a statistically non-significant rise in plasma calcium but no change in alkaline phosphatase concentrations.