For treatment of rickets, the Guideline for Vitamin D and Calcium in Children’ Committee has recommended a dose of 2000 IU/day of vitamin D orally for a minimum duration of 3 months to be followed up with maintenance doses. We have further recommended that larger doses may only be considered when compliance or absorption from gut is an issue, in infants over 3 months of age [1]. Thus, it is not a recommendation for ‘all’ infants.　

The Global Consensus Statement has recommended 2000 IU/day of vitamin D for a period of three months for treatment of rickets. Further, they have advised a 50,000 IU single dose if a bolus dose is to be given. The total dose received, if 2000 IU/day is administered as per their recommendations, comes to 180000 IU in 90 days, while the bolus dose is 50,000 IU [2]. This issue was considered by the Committee when all Guidelines were reviewed and after deliberation, the Committee decided on a weekly dose as advised by the Endocrine Society Clinical Practice Guideline [3]. Further, the Committee also decided on recommending 60,000 rather than 50,000 IU as a bolus dose as most preparations in the Indian markets contain 60,000 IU.

We agree that there is a limited evidence on dosage for treatment of rickets in infants; thus the Guideline clearly states that it is based on available evidence from Indian studies and other previously published recommendations, which were pertinent to the Indian circumstances. The authors of the query have quoted two studies that reported a rapid rise in vitamin D after 2-monthly bolus doses. The study by Huynh, et al. [4] demonstrated the efficacy of bolus dose vitamin D in newborn infants and concluded that bolus dosing of 50000 IU cholecalciferol achieves higher 25 (OH)D (repletion rates) at around 1-2 weeks of age compared to daily dosing, and they report no hypercalcaemia [4]. This study was on newborns (of mothers who had vitamin D concentrations below 75 nmol/L) and the enrolled infants were not diagnosed with rickets. The other study quoted in the query is by Shakiba, et al. [5], which is a randomized trial on 120 healthy breastfed infants. They also conclude that a bolus of 50,000 IU of vitamin D every two months with a routine vaccination program provides ideal serum concentrations of vitamin D [5]. They too do not report hypercalcemia, though the study was in infants who were 2.5-4 kg and did not have rickets.　

Regarding the second observation, while it is true that rickets does not occur in the age group of 3-10 years, it is also true that bone accrual takes place throughout childhood, and that peak bone mass is built up by second decade. Also, though evidence for extra-skeletal effects of vitamin D is still not compelling, adequate vitamin D status is advisable at all ages [6]. Further, as mentioned, the guideline is based on the assumption of minimal sun exposure; children and adolescents receiving adequate sunlight exposure or dietary vitamin D do not require supplementation.

1. Indian Academy of Pediatrics ‘Guideline for Vitamin D and Calcium in Children’ Committee, Khadilkar A, Khadilkar V, Chinnappa J, Rathi N, Khadgawat R, et al. Prevention and Treatment of Vitamin D and Calcium Deficiency in Children and Adolescents: Indian Academy of Pediatrics (IAP) Guidelines. Indian Pediatr. 2017;54:567-73.

2. Munns CF, Shaw N, Kiely M, Specker BL, Thacher TD, Ozono K, et al. Global Consensus Recommendations on Prevention and Management of Nutritional Rickets. J Clin Endocrinol Metab. 2016;101:394-415.

3. Holick MF, Binkley NC, Bischoff-Ferrari HA, Gordon CM, Hanley DA, Heaney RP, et al. Evaluation, Treatment, and Prevention of Vitamin D Deficiency: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2011;96:1911-30.　

4. Huynh J, Lu T, Liew D, Doery JC, Tudball R, Jona M, et al. Vitamin D in newborns. A randomised controlled trial comparing daily and single or albolus vitamin D in infants. J Paediatr Child Health. 2017;53:163-9.

5. Shakiba M, Sadr S, Nefei Z, Mozaffari-Khosravi H, Lotfi MH, Bemanian MH. Combination of bolus dose vitamin D with routine vaccination in infants: A randomised trial. Singapore Med J. 2010;51:440-5.