The clinical and biochemical presentation of vitamin D deficiency and insufficiency in children and adolescents.

Aim: To evaluate the clinical and biochemical findings of the children and adolescents with vitamin D deficiency and insufficiency in order to determine the clinical and biochemical presentation differences between age groups.

Methods: This retrospective study included a review of medical reports of 543 patients (aged between 1-17 years) who were referred to our hospital between October 2011 and May 2012 with symptoms related to vitamin D deficiency or insufficiency. The patients were divided into four groups by age: 1-3 years (Group 1), 4-6 years (Group 2), 7-11 years (Group 3) and 12-17 years (Group 4). Patients diagnosed with vitamin D deficiency or insufficiency were evaluated as to their clinical and biochemical findings.

Results: Gender distribution were not statistically different between the four groups. The mean ages of Groups 1-4 were 1.9±0.7, 5.1±0.9, 8.9±1.3, 13.1±1.1, respectively. Major complaints on admission were muscle weakness (91%), low weight gain (failure to thrive) (89%), head deformity (frontal bossing) (35.6%), bone deformity (enlargement of wrist and ankles) (29.7%) for Group 1. Muscle weakness (76%) and low weight gain (failure to thrive) (68%) for Group 2. Leg and chest pain were the major symptoms in Group 3 (57% and 28%, respectively) and in Group 4 (26% and 55%, respectively) as well as high rates of obesity (31% and 63%). The biochemical findings of vitamin D deficiency mostly appeared in the first group who developed vitamin D deficiency due to the lack of vitamin D supplementation. However, in older children, the majority of the patients had low 25 hydroxyvitamin D (25 OHD) values without evidence of biochemical findings of osteomalacia.

Conclusion: Depending on the degree of deficiency and insufficiency, and the age of the patients, the clinical and biochemical findings varied widely. Children under the age of 3 who either never received vitamin D supplementation or who had been receiving supplementation that was stopped too early were at a greater risk for developing clinically and biochemically proved vitamin D deficiency. In older children, low vitamin D levels mostly resulted in subtle complaints without abnormal biochemical findings.