1153 Rickets: 100 years on from Mellanby’s ‘accessory factor’

Abstract

<h3>Background</h3> This year marks the 100-year anniversary since Sir Edward Mellanby published ‘Experimental Rickets’, a culmination of 5 years of work investigating the cause of rickets. Preceded by largely qualitative work on the subject, Mellanby was adamant that ‘<i>all dietetics problems must ultimately submit to quantitative experiment’</i>. Mellanby identified that certain fats, in particular cod liver oil, had potent antirachitic properties and concluded ‘<i>there seems no longer any doubt that they contain some of the fat-soluble accessory food factor’.</i> He suggested, in children, the most common cause of rickets was ‘<i>a combination of relatively deficient anti-rachitic vitamin and excessive bread’</i> consequent to austerity during the first world war. McCollum et al supported this the following year, 1922, naming this ‘factor’ Vitamin D. Mellanby’s remarkable and methodical work laid the foundations for a better understanding of rickets and popularised the use of cod liver supplements in subsequent generations of children. <h3>Objectives</h3> To explore the historical development of our understanding and treatment of rickets, and the implications of these for current and future practice. <h3>Methods</h3> Literature review. <h3>Results</h3> In 1922, Harriette Chick of the British medical research council undertook trials involving children at the Vienna Kinderklinic, a paediatric clinic in a region particularly affected by rickets. Here she was able to demonstrate that rickets appeared curable by both cod liver oil and exposure to sunlight. The link between vitamin D and sunlight exposure remained elusive until two years later when Steenbock and Black were able to demonstrate that ultraviolet irradiation of Vitamin D containing food increased its activity. With scientific evidence and support, governments justified the commencement of a public health initiative fortifying common foodstuff with vitamin D, resulting in the near eradication of rickets in the USA and Canada. In the UK, mandatory fortification was legislated in 1940 when cases of rickets rose due to widespread malnutrition. Worsening air quality as a result of industrialisation was proposed to be a significant contributor to rickets by limiting exposure to UVB radiation. The introduction of the 1956 Clean Air Act, alongside fortification, is believed to have thus contributed to a reduction in the incidence of rickets. A series of deaths from idiopathic infantile hypercalcaemia in the years following raised concerns of an ‘epidemic of hypercalcaemia’ and led to a ban in fortification in 1953, with the exception of margarine, cereals and infant formula milk. <h3>Conclusions</h3> Today, Public Health England (PHE) advises that children over the age of 5 years require an average of 10 μg of vitamin D a day and should consider daily supplements during autumn and winter. However, with a new rise in the prevalence and incidence of nutritional rickets recently highlighted in the UK, over the last two decades, it brings into question whether we are doing enough to implement the current policy or the policy needs adapting. Future changes may require increasing awareness of the recommendation as well as a broader fortification strategy. Regardless of the approach, paediatricians are likely to play a vital role in reducing the incidence of this entirely preventable condition.