Single oral or single intramuscular dose of vitamin d in The treatment of vitamin d deficiency in children at Aga Khan University hospital, Nairobi: a randomized controlled trial

Background: Vitamin D deficiency is a global health concern and plays an important role in bone health and many chronic non-communicable diseases. Vitamin D deficiency in children is associated with short stature, underdevelopment, respiratory infections and many other features that increase the risk of childhood complications. The prevalence of vitamin D deficiency in Kenya among children is high. Treatment with daily oral vitamin D is associated with poor compliance. While a single high intramuscular dose vitamin D offers an alternative strategy, it is however, associated with injection site pain and its absorption is dependent on the patient’s peripheral circulation. Various studies have been conducted on different and appropriate strategies for the treatment of vitamin D deficiency. Currently available data report conflicting results. This study was designed to compare the effect of a single high dose of vitamin D3 administered orally versus a single high dose of Vitamin D3 administered intramuscularly in the treatment of vitamin D deficiency in children attending Aga Khan University Hospital, Nairobi. Objectives: The primary objective of this study was to compare serum vitamin D levels at Day One and at three months (ninety days) following administration of either a single high oral dose or single high intramuscular dose of vitamin D3 in children with laboratory confirmed vitamin D deficiency. The secondary objectives were to determine the relationship between serum vitamin D, parathyroid hormone and calcium levels pre and post treatment with vitamin D3 and to determine the side effects associated with both the single oral and single intramuscular vitamin D administration. Methods:This was a single blind two-arm randomized controlled trial in children aged three months to twelve years attending the paediatric ambulatory clinics or admitted to the children’s ward at Aga Khan University Hospital Nairobi. All children with laboratory-confirmed sub-optimal serum vitamin D levels (\u3c30ng/ml) in the above-named age categories, with parental or guardian consent, were recruited into the study. Vitamin D levels, parathyroid hormone (PTH) and calcium levels were measured at baseline. Children with sub-optimal serum vitamin D levels were randomized into two groups to receive either oral or intramuscular (IM) Vitamin D3.Calcium supplementation was done for four weeks. Vitamin D levels, parathyroid hormone (PTH) and calcium levels were measured at the end of three months and analysis performed using R Studio statistical software. Results: Out of the 106 children with Vitamin D deficiency enrolled into the study, 54 were randomly assigned to the intramuscular (IM) group while 52 to the oral group. The median age in the IM group was 18 months (IQR: 8-51) while in the oral group was 12 months (IQR: 6-27). Majority of the participants were male (56.6% vs 43.4%). Overall baseline vitamin D levels were 22.1 ng/ml (IQR:18.1 – 26.2). Between the IM and oral groups, the baseline vitamin D levels were not significantly different (P-value 0.38). Overall Vitamin D levels at three months were 43 ng/ml (IQR: 39-53) with no significant differences between the IM and oral groups (P-value 0.45). Calcium levels at baseline were 2.39 mmol/liter (IQR: 2.28-2.47) with no significant difference between the two study groups (P-value 0.85). At three months, the calcium levels were 2.38 mmols/liter (IQR: 2.28-2.41) with no significant difference in the two groups (P-value 0.77). While there was no correlation between calcium and Vitamin D throughout the observation period, there was a positive correlation between PTH levels and Vitamin D levels in the study (r=0.74). Conclusion: From the study there was a significant increase in the levels of Vitamin D between baseline and day ninety in both groups, supporting the currently recommended dosing. Both oral and IM methods of vitamin D administration therapy were thus effective in the correction of vitamin D deficiency in the age group studied. Our study further found PTH to be a good surrogate marker for vitamin D levels (r=0.76, P-value \u3c0.001) in children receiving supplementation