Calcium bioavailability from a new calcium-fortified orange beverage, compared with milk, in healthy volunteers

The recommended dietary calcium intake may be difficult to reach using dairy products only. This study aimed to evaluate the absorbability of calcium of a new orange beverage in comparison with that of milk. Ten healthy adults, 5 males and 5 females, were randomly divided to receive, under fasting conditions, an orange beverage enriched either with calcium or milk. Both the beverages had been labelled the previous evening with a Ca-44 solution. After a two-month interval the subjects underwent a crossover of beverages. Total and ionized calcium, parathyroid (PTH) hormone, and Ca-44 were evaluated. The Ca-44 was measured by inductively coupled plasma spectrometry. The relative changes in calcium absorption from the two test drinks were similar (23.0 +/- 6.4% for milk and 20.9 +/- 9.1 % for the orange beverage). No significant differences were found between the two test groups. Both milk and orange beverage determined a similar and significant (p < 0.001) decrease in serum PTH two hours after the beginning of the test (-22.1 +/- 14.0% for milk and -27.9 +/- 15.3% for orange beverage). We can conclude that the bioavailability of calcium from this new calcium-enriched orange beverage is similar to that of milk.