Incidence rate and characteristics of symptomatic vitamin D deficiency in children: a nationwide survey in Japan

• Published in: ENDOCRINE JOURNAL Vol. 65; no. 6; pp. 593 - 599
• Main Authors: Kubota, Takuo, Nakayama, Hirofumi, Kitaoka, Taichi, Nakamura, Yosikazu, Fukumoto, Seiji, Fujiwara, Ikuma, Hasegawa, Yukihiro, Ihara, Kenji, Kitanaka, Sachiko, Koyama, Satomi, Kusuda, Satoshi, Mizuno, Haruo, Nagasaki, Keisuke, Oba, Koji, Sakamoto, Yuko, Takubo, Noriyuki, Shimizu, Toshiaki, Tanahashi, Yusuke, Hasegawa, Kosei, Tsukahara, Hirokazu, Yorifuji, Tohru, Michigami, Toshimi, Ozono, Keiichi
• Format: Journal Article
• Language: English
• Published: Japan The Japan Endocrine Society 01.01.2018; Japan Science and Technology Agency
• Subjects: Age; Breast feeding; Children; Epidemiology; Hospitals; Hypocalcemia; Nationwide survey; Nutrient deficiency; Patients; Public health; Rickets; Vitamin D; Vitamin D deficiency; Vitamin deficiency; Japan; Vitamin D deficiency; Children; Nationwide survey; Rickets; Hypocalcemia
• ISSN: 0918-8959; 1348-4540
• DOI: 10.1507/endocrj.EJ18-0008

There is concern that vitamin D deficiency is prevalent among children in Japan as well as worldwide. We conducted a nationwide epidemiologic survey of symptomatic vitamin D deficiency to observe its incidence rate among Japanese children. A questionnaire inquiring the number of new patients with vitamin D deficiency rickets and/or hypocalcemia for 3 years was sent to 855 randomly selected hospitals with a pediatrics department in Japan. In this survey, we found that 250 children were diagnosed with symptomatic vitamin D deficiency. The estimated number of patients with symptomatic vitamin D deficiency per year was 183 (95% confidence interval (CI): 145–222). The overall annual incidence rate among children under 15 years of age was 1.1 per 100,000 population (95% CI: 0.9–1.4). The second survey has provided detailed information on 89 patients with symptomatic vitamin D deficiency under 5 years of age in hospitals in the current research group. The nationwide and second surveys estimated the overall annual incidence rate of symptomatic vitamin D deficiency in children under 5 years of age to be 3.5 (2.7–4.2) per 100,000 population. The second survey revealed 83% had bowed legs, 88% had exclusive breastfeeding, 49% had a restricted and/or unbalanced diet and 31% had insufficient sun exposure among the 89 patients. This is the first nationwide survey on definitive clinical vitamin D deficiency in children in Japan. Elucidating the frequency and characteristics of symptomatic vitamin D deficiency among children is useful to develop preventative public health strategies.