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

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. 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. 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. 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.