Abstract:  The absorption of calcium,the effects on calcium absorption of different particle sizes and the method to improve calcium absorption rate were studied in this article.The results showed that ultramicro bone powder was a good calcium resource.The particle size could affect calcium absorption and utilization,CPP can improve calcium absorption of ultramicro bone powder.

Key words: Calcium Ultramicro bone powedr Calaium metabolism Casein phosphopeptide (CPP)