Case of incidentally diagnosed vitamin D deficiency rickets: A review of literature from Japan and a proposal for reintroduction of vitamin D₂

Abstract

Key wordsbreast-feeding, Japan, sunlight exposure, vitamin D deficiency rickets, vitamin D supplementation.Recent research in rickets in Japan has focused on hereditary rickets, that is, X-linked hypophosphatemic vitamin D resistant rickets 1 or vitamin D-dependent rickets. 2 It was speculated that the advent of vitamin D-fortified milk and enhanced sunlight exposure decreased the previously common incidence of vitamin D deficiency rickets. However, vitamin D deficiency rickets continues to be reported in USA due to dietary restrictions without the benefit of adequate sunlight exposure or vitamin D supplementation and/or prolonged breast-feeding in dark-skinned infants. 3 Vitamin D levels in human milk (approximately 4.5 IU/dL) are generally low in comparison with vitamin D-fortified milk (about 50 IU/dL). 4 Therefore, a uniform policy of vitamin D supplementation has recently been recommended for breastfed infants in the USA. 3 Nineteen patients of vitamin D deficiency rickets due to dietary restrictions and/or lack of sunlight exposure between 1995 and 2000 were reported in Japan. [5][6][7][8][9][10][11][12] We describe one case of vitamin D deficiency rickets in Tochigi, not due to dietary restriction, and review recent reports written in English on vitamin D deficiency rickets in Japan. [5][6][7][8][9][10][11][12]

Nutritional rickets around the world: causes and future directions

“…Children with rickets tend to have dietary restrictions resulting in low 25(OH)D values and hypocalcaemia. 85,86 However, vitamin D deficiency is expected to increase in Japan because the sale of vitamin D syrup and multivitamin granules including vitamin D was stopped.…”

A Spectrum of Clinical Presentations in Seven Japanese Patients with Vitamin D Deficiency

“…Vitamin D deficiency has been increasingly reported in recent years, particularly among children (1, 2). Diet and sunlight exposure are the main determinants of vitamin D levels, and thus inadequate vitamin D acquisition through either poor dietary intake or limited sunlight exposure leads to depletion of vitamin D stores.…”

Vitamin D status of mothers and their neonates in Kuwait

“…Since then it has been eliminated both from the developed world as well as from the developing countries. Recently, this condition has been reappearing in many parts of the world including some industrialized countries 1–5 . A higher incidence has been reported from many affluent Arab countries having plenty of sunshine 6–8 .…”