Children with type I spinal muscular atrophy commonly demonstrate reduced bone mineral density. Our objectives were to evaluate and assess adequacy of vitamin D intake, serum levels, and association with bone mineral density. Assessments were completed using 3-day food records and dual energy x-ray absorptiometry scans. The spinal muscular atrophy type I cohort included 22 males and 18 females (N = 40), with a mean age of 18.6 months. Data collection occurred from 2001 to 2011. Seventy-five percent of patients had inadequate intake of vitamin D at the initial visit. Using mixed-effects analyses, vitamin D and calcium intakes correlated positively with bone mineral density (r = 0.31 and r = 0.53, respectively). Increased vitamin D and calcium consumption were associated with an increase in bone mineral density (P = .04 and P = .01, respectively). Vitamin D intake correlated positively with serum levels (r = 0.65). Further study is needed to determine optimal intakes of vitamin D and calcium in the spinal muscular atrophy type I population.
Keywords: SMN1; bone mineral density; spinal muscular atrophy type I; vitamin D.