Objective: The effect of adult-type hypolactasia, caused by the lactase-phlorizin hydrolase C/C-13910 genotype, on growth is unknown. We studied whether this polymorphism was associated with body height growth, the use of milk products, or dietary calcium intake.
Methods: A prospective cohort study was performed among 3596 randomly selected Finnish children and adolescents (3-18 years of age) in 1980, with reexamination in 1983, 1986, and 2001 (after a 21-year follow-up period). Lactase-phlorizin hydrolase C/T-13910 polymorphism was determined for 2265 participants in 2002. Nutrient intakes were measured for 1137, 858, and 1031 subjects in 1980, 1986, and 2001, respectively.
Results: The lactase-phlorizin hydrolase C/T-13910 polymorphism was not related to mean height growth speed for either boys or girls or to final mean body height in adulthood. The consumption of milk products, protein, and calcium was lowest for female subjects with the lactase-phlorizin hydrolase C/C-13910 genotype over the study years, but there were no genotype-related differences in the intake of vitamin D. For boys, significant differences were found in the consumption of milk products but not in the mean dietary intake of calcium, protein, or vitamin D.
Conclusions: The lactase-phlorizin hydrolase C/C-13910 genotype was not associated with mean growth speed or final mean body height for either boys or girls. However, it contributed significantly to milk product consumption and dietary calcium intake from childhood into young adulthood.