We read with interest the recent article in Indian Pediatrics by Shah,
et al. [1], and have the following comments to offer:
Though the authors have excluded patients with known
parathyroid disease, rickets, renal tubular acidosis, chronic kidney
disease or a diagnosis of acute kidney injury at admission, about 56%
children were stated to have some underlying chronic illness. One would
be really interested to know the nature of these chronic illnesses, as
many diseases such as chronic liver disease [2] and nephrotic syndrome
[3] are known to have low vitamin D levels. The authors have also not
mentioned whether any of these children with chronic diseases were on
long-term medications known to affect vitamin D-calcium-parathyroid axis
such as Cortisteroids for nephrotic syndrome, Rifampicin for
tuberculosis, and antiepileptics for epilepsy [4]. Authors stated that
15 patients were admitted with liver disease and 24 with neurological
diseases; the disease condition and/or the medication used in these
children can lead to a decrease in vitamin D and calcium levels.
In this study, ‘parathyroid-responder’ was defined as
children with serum parathyroid hormone (PTH) >65 ng/mL with 25(OH)D <20
ng/mL, and/or calcium corrected for albumin <8.5 mg/dL. But it is not
clear why the authors chose to analyze children with hyperparathyroidism
secondary to 25(OH)D deficiency alone, and leave out non-vitamin
D-deficient children with hypocalcemia-related hyperparathyroidism.
It would have been useful to evaluate the ionized
calcium (iCa) levels of these critically-ill children in addition to the
total calcium adjusted for albumin. Though iCa levels are nor reported,
in view of very high incidence (59%) of hypocalcemia in the study
population, one would be really inquisitive in knowing whether calcium
supplemention was given to the hypocalcemic children, especially to
those with septic shock.
The authors mention that data regarding type of
milk-product consumption by the children was recorded but the same has
not been presented in the results.
We would also like to point out to few errors: the
unit for serum 25-hydroxy vitamin D level used in abstract is ‘µg/mL’
instead of ‘ng/mL’; the abstract also mentions the non-vitamin
D-deficient children to be 19.8%, whereas, it should be 16.9%.
1. Shah SK, Kabra SK, Gupta N, Pai G, Lodha R.
Vitamin D deficiency and parathyroid response in critically-ill
children: Association with illness severity and clinical outcomes.
Indian Pediatr. 2016;53:479-84.
2. Iruzubieta P, Terán Á, Crespo J, Fábrega E.
Vitamin D deficiency in chronic liver disease. World J Hepatol.
2014;6:901-15.
3. Freundlich M, Bourgoignie JJ, Zilleruelo G,
Abitbol C, Canterbury JM, Strauss J. Calcium and vitamin D metabolism in
children with nephrotic syndrome. J Pediatr. 1986;108:383-7.
4. Gröber U, Kisters K. Influence of drugs on vitamin
D and calcium metabolism. Dermatoendocrinology. 2012;4: 158-66.