In a community-based population in the US, the incidence of nutritional rickets in children younger than 3 years was 24.1 per 100,000 for the decade beginning in 2000.[8]Thacher TD, Fischer PR, Tebben PJ, et al. Increasing incidence of nutritional rickets: a population-based study in Olmsted County, Minnesota. Mayo Clin Proc. 2013 Feb;88(2):176-83.
http://www.ncbi.nlm.nih.gov/pubmed/23374621?tool=bestpractice.com
Nutritional rickets is associated with black and South Asian ethnicity, and with breast-feeding.[4]Nield LS, Mahajan P, Joshi A, et al. Rickets: not a disease of the past. Am Fam Physician. 2006 Aug 15;74(4):619-26.
https://www.aafp.org/afp/2006/0815/p619.html
http://www.ncbi.nlm.nih.gov/pubmed/16939184?tool=bestpractice.com
[8]Thacher TD, Fischer PR, Tebben PJ, et al. Increasing incidence of nutritional rickets: a population-based study in Olmsted County, Minnesota. Mayo Clin Proc. 2013 Feb;88(2):176-83.
http://www.ncbi.nlm.nih.gov/pubmed/23374621?tool=bestpractice.com
[9]Weisberg P, Scanlon KS, Li R, et al. Nutritional rickets among children in the United States: review of cases reported between 1986 and 2003. Am J Clin Nutr. 2004 Dec;80(6 Suppl):1697S-705S.
https://academic.oup.com/ajcn/article/80/6/1697S/4690514
http://www.ncbi.nlm.nih.gov/pubmed/15585790?tool=bestpractice.com
[10]Julies P, Lynn RM, Pall K, et al. Nutritional rickets under 16 years: UK surveillance results. Arch Dis Child. 2020 Jun;105(6):587-92.
http://www.ncbi.nlm.nih.gov/pubmed/31949032?tool=bestpractice.com
The peak incidence of rickets is between 6 and 23 months, with a further peak among adolescents ages 12 to 15 years.[11]World Health Organization. Nutritional rickets: a review of disease burden, causes, diagnosis, prevention and treatment. November 2019 [internet publication].
https://www.who.int/publications/i/item/9789241516587
Globally, nutritional deficiencies are the leading cause of rickets, followed by vitamin D-dependent, vitamin D-resistant, and renal rickets. Surprisingly, in the sunniest areas of the world, rickets is still a major health problem. Reasons for this may include sociocultural factors (such as burka-wearing practices, an increase in sedentary lifestyles, less time spent outdoors), foods unfortified with vitamin D, and diets low in calcium.[12]Holick MF. Resurrection of vitamin D deficiency and rickets. J Clin Invest. 2006 Aug;116(8):2062-72.
https://www.jci.org/articles/view/JCI29449
http://www.ncbi.nlm.nih.gov/pubmed/16886050?tool=bestpractice.com
[13]Gupta P, Dabas A, Seth A, et, al. Indian Academy of Pediatrics revised (2021) guidelines on prevention and treatment of vitamin D deficiency and rickets. Indian Pediatr. 2022 Feb 15;59(2):142-58.
https://www.indianpediatrics.net/feb2022/142.pdf
http://www.ncbi.nlm.nih.gov/pubmed/34969941?tool=bestpractice.com
Increased skin pigmentation is associated with reduced capacity to synthesize cholecalciferol. Increased sunscreen use has also been implicated in vitamin D deficiency.[14]Diehl JW, Chiu MW. Effects of ambient sunlight and photoprotection on vitamin D status. Dermatol Ther. 2010 Jan-Feb;23(1):48-60.
http://www.ncbi.nlm.nih.gov/pubmed/20136908?tool=bestpractice.com
Of the genetic causes of rickets, the most common is X-linked hypophosphatemic rickets, with a prevalence of 1 in 20,000.[6]Alizadeh Naderi AS, Reilly RF. Hereditary disorders of renal phosphate wasting. Nat Rev Nephrol. 2010 Nov;6(11):657-65.
http://www.ncbi.nlm.nih.gov/pubmed/20924400?tool=bestpractice.com
The prevalence of X-linked hypophosphatemic rickets is estimated to be between 16 per million and 50 per million.[6]Alizadeh Naderi AS, Reilly RF. Hereditary disorders of renal phosphate wasting. Nat Rev Nephrol. 2010 Nov;6(11):657-65.
http://www.ncbi.nlm.nih.gov/pubmed/20924400?tool=bestpractice.com
[15]Rafaelsen S, Johansson S, Ræder H, et al. Hereditary hypophosphatemia in Norway: a retrospective population-based study of genotypes, phenotypes, and treatment complications. Eur J Endocrinol. 2016 Feb;174(2):125-36.
https://www.doi.org/10.1530/EJE-15-0515
http://www.ncbi.nlm.nih.gov/pubmed/26543054?tool=bestpractice.com
In children presenting with a new diagnosis of rickets, vitamin D deficiency and X-linked hypophosphatemic rickets are diagnosed at similar rates. Other genetic causes (mutations in vitamin D 25-hydroxylase or 1-alpha-hydroxylase enzymes, or in the vitamin D receptor, or autosomal dominant and autosomal recessive hypophosphatemic rickets) are very rare.