Figure 4

Multivariable adjusted dose-response associations between average dietary calcium intake during adolescence and HAZ from adolescence to young adulthood in boys and girls with plant-based diet. Multivariable adjusted dose-response curves were indicated by solid line and 95% confidence interval by dashed lines. Calcium intake were coded using an RCS function with four knots, represented by dots, located at the 5th, 35th, 65th, and 95th percentiles of the distribution of average intake of dietary calcium. Y-axis represents the difference in height-for-age z-score between individuals with any value of calcium intake with individuals with 400 mg/d of calcium intake. Model A and B, using full data from 1989 to 2011, were adjusted for age, weight, year of birth, paternal and maternal height, urbanization index, latitude, DNR, average dietary intake of total energy, average energy adjusted dietary intakes of protein, vitamin A, iron, and zinc during adolescence, stratum, and household income level. Model C and D, only using data since 1997, and additionally adjusted for physical exercises level during growth. HAZ: height-for-age z-score; RCS: restricted cubic spline; DNR: annual average direct normal radiation.