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Nutritional rickets around the world

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Abstract

Nutritional rickets is a major public health problem in many countries of the world. The disease is characterized by deformities of the long bones, enlargement of the wrists and costochondral junctions, hypotonia and, in infants, craniotabes and delayed fontanelle closure. Predominantly caused by severe vitamin D deficiency, rickets can also be associated with hypocalcemic seizures and cardiac failure. First presentation is typically at 6–24 months of age, although hypocalcemia may be evident in younger infants. In many affluent industrialized countries, the prevalence of rickets in the general population diminished after the introduction of clean-air legislation and dietary supplementation. However, in such countries, vitamin-D deficiency rickets has re-emerged in recent years, particularly among groups with limited exposure to UVB-containing sunshine. Infants at risk of rickets tend to be those whose mothers had poor vitamin D status during pregnancy and those exclusively breast-fed for a prolonged period with little skin exposure to UVB. In other countries of the world, the prevalence of rickets can be high, even in regions with abundant year-round UVB-containing sunshine. In general, this is also due to vitamin D deficiency related to limited sun exposure. However, reports from Africa and Asia suggest that there may be other etiological factors involved. Studies in South Africa, Nigeria, The Gambia and Bangladesh have identified rickets in children, typically 3–5 years old at first presentation, in whom plasma 25-hydroxyvitamin D concentrations are higher than those characteristic of primary vitamin D deficiency. Calcium deficiency has been implicated, and in some, but not all, disturbances of phosphate metabolism, renal compromise and iron deficiency may also be involved. Continuing studies of the etiology of nutritional rickets will provide evidence to underpin guidelines for the prevention and treatment of rickets world-wide.

This article is part of a Special Issue entitled ‘Vitamin D Workshop’.

Highlights

▸ The greatest burden of nutritional rickets is in Africa, the Middle East and Asia. ▸ It is re-emerging in many industrialized countries especially in some ethnic groups. ▸ D deficiency is the main cause even in sunny places, due to limited skin exposure. ▸ Rickets without severe hypovitaminosis D is associated with very low Ca intakes. ▸ Prevention or cure based on vitamin D status will be ineffective in such cases.

Section snippets

Rickets

Rickets is a disease of children characterized by a failure or delay in endochondral calcification of the growth plates of long bones [1]. This results in widening and splaying of the growth plates and leads to enlargement of the wrists and costochondral junctions, and the characteristic deformities of the lower limbs, notably genu varum (bow legs) and genu valgum (knock-knees). Rickets is generally accompanied by osteomalacia, i.e. defective mineralization of preformed osteoid in bone,

Rickets prevalence world-wide

Rickets was common in Europe until the mid- 20th century and was known as “The English Disease” because of its high prevalence in England. The seminal work of pioneers such as Harriette Chick and Elsie Dalyell demonstrated that this was due to vitamin D deficiency [4]. In their studies in a children's hospital in Vienna immediately after World War I, they demonstrated that rickets could be prevented and cured by being in the sunlight outdoors, in the summer not winter, or by exposure to mercury

Causes of nutritional rickets world-wide

Vitamin D deficiency appears to the major factor underlying nutritional rickets in many countries world-wide [23], [24], even in ‘sun-rich’ countries where there is year-round opportunity for skin exposure to UVB-containing sunlight [25], [26], [27]. Vitamin-D deficiency rickets is often first diagnosed in infancy or young childhood and is frequently associated with limited skin sunshine exposure of the mother and child [1]. There are many reasons for such limitations, including wearing

Calcium-deficiency rickets

Reports from South Africa and Nigeria have suggested that calcium deficiency is a major factor in the etiology of rickets in those countries [2], [29], and have demonstrated that some affected children respond well to treatment with calcium alone [32].

A few years ago we reported a case series of patients in The Gambia with bone deformities consistent with rickets who had a similar clinical profile at presentation to that reported from Nigeria and South Africa [28]. The Gambia is a tropical West

Nutritional rickets of mixed etiology

The hypothesis we proposed to explain the etiology of rickets in The Gambia neatly described the presenting biochemical features and response to vitamin D treatment. However, it could not explain why some Gambian children develop rickets while the majority do not, given that most children in that country have very low calcium intakes, of around 200–300 mg/d [37]. Similarly in Nigeria, low calcium intakes alone were not considered to fully account for the rickets seen in that country [29]. In

Concluding remarks

There is an unacceptably high world-wide prevalence of nutritional rickets, a preventable disabling disease of children. The greatest burden is in Africa, the Middle East and Asia, and, increasingly, in families originating from these countries resident in Europe, Australasia and the Americas. For many children, vitamin D deficiency is the predominant cause and is associated with limited UVB exposure by the mother before and during pregnancy and subsequently by the child. For such children the

Acknowledgements

Funded by the UK Medical Research Council under programmes U105960371 and U123261351. I would like to thank all members of my research group, past and present, my collaborators around the world, and the children and their parents who have contributed to the studies and development of ideas described in this paper.

References (47)

  • V. Braithwaite et al.

    Follow-up study of Gambian children with rickets-like bone deformities and elevated plasma FGF23: possible aetiological factors

    Bone

    (2012)
  • V. Braithwaite et al.

    Iron status an fibroblast growth factor-23 in Gambian children

    Bone

    (2012)
  • J.M. Pettifor

    Nutritional rickets

  • M.Z. Mughal

    Rickets

    Current Osteoporosis Reports

    (2011)
  • Scientific Advisory Committee on Nutrition

    Update on Vitamin D

    (2007)
  • A. Prentice

    Vitamin D deficiency: a global perspective

    Nutrition Reviews

    (2008)
  • N.J. Shaw et al.

    Vitamin D deficiency in UK Asian families: activating a new concern

    Archives of Disease in Childhood

    (2002)
  • S.F. Ahmed et al.

    Recent trends and clinical features of childhood vitamin D deficiency presenting to a children's hospital in Glasgow

    Archives of Disease in Childhood

    (2011)
  • S. Ashraf et al.

    The prevalence of rickets among non-Caucasian children

    Archives of Disease in Childhood

    (2002)
  • E. Odeka et al.

    Nutritional rickets is increasingly diagnosed in children of ethnic origin

    Archives of Disease in Childhood

    (2005)
  • S.S. Beck-Nielsen et al.

    Incidence and prevalence of nutritional and hereditary rickets in southern Denmark

    European Journal of Endocrinology/European Federation of Endocrine Societies

    (2009)
  • A. Prentice et al.

    Nutrition and bone growth and development

    Proceedings of the Nutrition Society

    (2006)
  • U. Tserendolgor et al.

    Prevalence of rickets in Mongolia, Asia Pacific

    Journal of Clinical Nutrition

    (1998)
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    Funded by the UK Medical Research Council, programmes U105960371 and U123261351.

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