Mother-child vitamin D deficiency: an international perspective

Rickets is often considered a 19th century disease. However, despite the availability of vitamin D and demonstration of its efficacy in preventing rickets, vitamin D deficiency rickets still exists as a public health problem with significant morbidity in the Middle East1^–5 and in many Asian countries,6 7 and has been reported with increasing prevalence in minority groups in North America8^–10 and in immigrant populations in Europe, Australia and New Zealand.11 In many countries, there are reports of a high prevalence of subclinical vitamin D deficiency in children and adolescents12 13 and rickets may merely represent the tip of the iceberg.

With more studies, there are reports from many countries of a high prevalence of vitamin D deficiency in women of child-bearing age14^–20 and during pregnancy21^–24 and in nursing mothers,25^–27 with likely adverse consequences for women, the fetus and growing infants and children.21 What seemed to be a rare entity has become so common that by the end of 2006 a lot of literature had been published that linked vitamin D deficiency with long-latency diseases, with the implication that vitamin D affects all organ systems, not just calcium and bone.

In addition to rickets and other possible consequences of disturbed calcium homeostasis,12 epidemiological evidence suggests that lack of vitamin D supplements in infancy and early childhood may increase the incidence of type 1 diabetes.28 29 In adults, new evidence30 supports the role of vitamin D in maintaining innate immunity and in the prevention of certain disease states including autoimmune diseases, multiple sclerosis,31 32 systemic lupus erythematosis,33 rheumatoid arthritis,34 some forms of cancer (breast, ovarian, …