Methodological comparison of dietary calcium intake estimations in residents of Hangzhou municipality

ObjectiveTo study dietary calcium intake in residents of Hangzhou municipality and to compare the results derived from China Food Composition(CFC)and food sample measurement of total diet consumption.MethodsBoth food weighting and food recording were conducted among 1 744 community residents(7-95 years old)selected with stratified cluster random sampling to collect information on total food consumption during 3 continuous days.Individual calcium intake was then calculated using both measurement results and data from CFC and compared with dietary reference intakes(DRIs)to analyze the correlation between the results derived from the two methods.ResultsThe median of daily dietary calcium intake ranged from 385.9-610.1 mg/d(CFC derived)and 303.9-544.2 mg/d(measurements derived)among the residents of different groups.All results derived from the measurements were lower than those of derived from CFC except for the urban male residents aged 14-17 years(P<0.001),with the Spearman correlation coefficients of 0.712-0.911(P<0.05).The proportions of the residents with adequate calcium intake(recommended nutrient intake,RNI)were 6.9% and 6.1% (CFC derived)for urban residents and 1.8% and 0.3% (CFC derived) for sub-urban residents,respectively.ConclusionDietary calcium intake is prevailingly insufficient among the residents of Hangzhou municipality.The calcium intake estimation derived from measurements is lower than that of CFC,although there is a close correlation between the estimations derived from the two methods.