Background: Few studies look at vitamin D levels in children living in sunny climates as it is assumed that they receive adequate vitamin D from sun exposure. In light of changing lifestyles of children and studies documenting vitamin D deficiency among children in extreme climates, a study to examine vitamin D levels in healthy children living in a luminous climate was conducted.
Methods: A retrospective chart review of vitamin D levels in healthy children with vague musculoskeletal pain (such as "growing pains") was done. Healthy children, specifically without musculoskeletal pain, were prospectively recruited as controls.
Results: Eighty-eight children, 42 children with "pain" and 46 controls were studied. No statistical difference in vitamin D levels was found between the "pain" group (mean vitamin D level 29.1 ng/mL) and the control group (mean vitamin D level 32.4 ng/mL, P<0.52). Overall, 14% of the entire group had levels <20 ng/mL, 49% had levels <30 ng/mL, and 15% had levels >40 ng/mL.
Conclusions: A consensus has yet to be established as to what an "optimal" vitamin D level is for growing children to develop strong bones for a lifetime. This study demonstrated that 14% of children living in a sunny climate had vitamin D levels below 20 ng/mL, a level universally accepted as insufficient, and 49% were below 30 ng/mL, arguably a "desired" level. A sunny climate does not assure vitamin D sufficiency. Virtually all children should be supplemented, with laboratory follow-up for those at high risk for low bone density/those with insufficiency fractures.