Bolded text denotes significant or marginally-significant relationships. Denominator degrees of freedom were 156 or 160 for Jonaskop and 54 or 73 for Kirstenbosch. For Aa and g, missing data for 17 seedlings in June 2009 were imputed and analyzed in Proc MIANALYZE (see methods for details).

aAll n  =  6603 (except transferrin receptor).bThe n for the imputed mean for transferrin receptor is 3295; based on 2003–2006 survey years only.cAll variables were available in original data set, so no 95% CI were generated by PROC MIANALYZE.Weighted descriptive statistics for study variables for women aged 18–49 who participated in the NHANES physical examination during 1999–2006, before and after multiple imputation of missing values.

The two gardens were analyzed separately using Proc MIXED with repeated measures on seedlings and an unstructured (UN) covariance structure. Log transformations were performed as needed to improve the normality of residuals. n = 52 plants for Kirstenbosch (except SLA with 51) and 161 for Jonaskop. Sixteen missing values for Aa and g were imputed with proc MI and MIANALYZE in SAS 9.3. Log transformations were used on stomatal density, pore index, and conductance. Asterisk indicates theta values from MIANALYZE rather than F-values.