The risks of vitamin D deficiency in children: asthma, diabetes and obesity

The Health supplement of La Repubblica of Tuesday 8 October publishes a commentary ahead of the national day against obesity called for tomorrow, 10 October, by the Italian Association of Dietetics and Clinical Nutrition.

The topic is a hot one: a vitamin D deficiency in childhood is said to be linked to the development of obesity, diabetes and various respiratory tract infections. Confirming these findings are several university professors interviewed by the newspaper, such as Prof. Miraglia del Giudice, paediatrician at the Università Federico II in Naples, and Dr. Giuseppe di Mauro, president of SIPPS (the Italian society of preventive and social paediatrics).

The link between vitamin D and obesity would appear to be bidirectional: on the one hand it is obesity that induces a vitamin D deficiency, on the other this deficiency contributes to the development of the problem. In the winter months there is an increase in sedentary behaviour, which in itself promotes weight gain, and exposure to sunlight, the main source of vitamin D assimilation, is reduced. The vicious circle is completed by the fact that vitamin D assimilation is further reduced by adipose tissue, which tends to retain it.

But there is more. In some way vitamin D acts on muscle cells, increasing their sensitivity to insulin. A vitamin D deficiency would therefore lead to increased insulin resistance, from which diabetes can develop.

A vitamin D deficiency would also have the effect of increasing the reactivity of the airways, with all the associated risks, from the increase in corticosteroids in asthma to the conditions linked to a rise in eosinophils.