If in doubt give vitamins; consider iron too, and remember other vulnerable children

Papers p 28 Clinical review p 39

Although frank rickets is now uncommon, a steady (some think increasing) trickle of new cases remains, and many local studies have shown high prevalences of suboptimal plasma vitamin 25-OH cholecalciferol (<=25 nmol/l) concentrations, particularly in winter. A paper this week by Lawson and Thomas (p 28) confirms a high prevalence (20-34%) in a representative sample of 618 Asian toddlers aged 11/2-21/2 years.1 Does this matter and what can we do about it?

Whether a low concentration of vitamin D itself is harmful is not known. The appearance of radiological abnormalities may depend on other factors affecting the availability of dietary calcium as well as vitamin D. We should be wary of chasing biochemical normality without evidence of clinical benefit, particularly if substances which are toxic in high doses have to be used. The overenthusiastic use of vitamin D supplements and fortified infant foods led to an epidemic of infant hypercalcaemia 40 years ago, with significant mortality and neurological deficit.2

The association of low plasma vitamin D and iron deficiency anaemia shown by Lawson and Thomas confirms a previous smaller study …