Nutritional rickets and vitamin D deficiency: consequences and strategies for treatment and prevention

ABSTRACT

Introduction

Rickets is typically characterized by bone deformities due to defective bone mineralization and chondrocyte maturation in growing bones. However, infantile rickets often goes unrecognized, because the skeletal abnormalities are more subtle and often can only be detected radiologically. Nutritional rickets is a major public health concern in several regions worldwide. It is most commonly caused by vitamin D and/or calcium deficiency.

Area covered

We provide an overview of historical perspective, epidemiology, and pathophysiology of nutritional rickets. Additionally, we outline diagnostic approaches and highlight challenges in radiographic diagnosis of rickets. Finally, we present strategies for prevention and treatment of rickets.

Expert opinion

Despite the evidence from clinical databases that rickets is a rare disease, it is likely that rickets is clinically underdiagnosed as studies designed to screen healthy children for radiographic evidence of rickets reported surprisingly much higher prevalence. It has been reported that some of the radiologic features of rickets can be misinterpreted as fractures. To prevent nutritional rickets, most if not all infants and young children, should receive vitamin D from formulas and foods that are fortified with vitamin D or supplementation to achieve a serum 25-hydroxyvitamin D of at least 20 ng/mL as recommended by the Institute of Medicine. It has been recommended by the Endocrine Society that to achieve maximum bone health for children and adults, a serum concentration of 25-hydroxyvitamin D should be at least 30 ng/mL and preferably 40–60 ng/mL. Pregnant women who are unable to obtain an adequate amount of vitamin D from sunlight exposure and natural and fortified diets should take a vitamin D supplement of 1500–2000 IUs daily as recommended by the Endocrine Society since it has been demonstrated that 600 IUs daily will not maintain a circulating 25-hydroxyvitamin D of at least 20 ng/mL and most pregnant women. If lactating women take approximately 6400 IUs of vitamin D daily, they provide enough vitamin D in their milk to satisfy their infant’s requirement thereby preventing rickets.

KEYWORDS:

• Rickets
• nutritional rickets
• vitamin D deficiency
• calcium deficiency
• fractures
• osteomalacia
• nonaccidental trauma
• vitamin D

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Correction

Article highlights

1. Although nutritional rickets due to vitamin D and/or calcium deficiency is reported to be rare, it is likely that rickets is clinically underdiagnosed as studies that were designed to screen asymptomatic children for radiographic evidence of rickets reported disproportionately high incidence in certain populations.

2. Vitamin D and/or calcium deficiency causes secondary hyperparathyroidism and increased phosphaturia and hypophosphatemia resulting in not only mineralization defect but also increased risk of fragility fractures.

3. Radiographically rickets can present not only with low-energy fractures but some features of healing rickets can mimic growth plate trauma.

4. To prevent nutritional rickets, serum 25-hydroxyvitamin D should be raised higher than 15 ng/mL and adequate calcium intake should be ensured. However, it is reasonable to achieve and maintain a circulating concentration of 25(OH)D of at least 30 ng/mL to prevent any evidence for osteomalacia, which is a component of rickets.

5. Vitamin D derived from sunlight exposure and natural diets is unlikely to meet the body’s requirement in most children and adults. To prevent nutritional rickets, most if not all infants and children should receive adequate calcium intake and vitamin D fortification or supplementation to achieve the desired level of serum 25-hydroxyvitamin D.

Declaration of interest

MF Holick has served as a consultant for Biogena Inc., Ontometrics Inc. and Solius Inc, and has grants from Carbogen Amcis BV and Solius Inc.

The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.