Vitamin D deficiency in childhood: old lessons and current challenges

Abstract

Hypovitaminosis D in childhood is a re-emerging public health problem in developed countries. New life style habits, current "epidemics" of obesity in children and adolescents worldwide, and other preventable risk factors may play a role in favoring the occurrence of vitamin D deficiency. In addition to skeletal consequences, hypovitaminosis D has been found to be involved in the development of serious health extra-skeletal problems in childhood, including atopy and autoimmunity. The increasing concerns about the global health impact of vitamin D deficiency make further research necessary to fill the gaps of knowledge in this field, and particularly to establish universally accepted "normal" serum 25(OH)D levels in the pediatric population, and to improve strategies for the screening, prevention and treatment of hypovitaminosis D. This review discusses the key points of hypovitaminosis D in childhood in the light of new knowledge, and highlights the limitations of current strategies to control this condition.

Family‐related factors may affect serum vitamin D levels

“…Epidemiological studies have shown that it can lead to rickets in children and osteomalacia in adults and may play a role in a variety of extraskeletal disorders, including asthma, type 1 diabetes, infectious and cardiovascular diseases and cancer. 3,4 The current epidemic of obesity is a challenging public health issue worldwide, 5 (35.3%) had vitamin D deficiency, defined as 10-20 ng/mL, and two (2.9%) had a severe vitamin D deficiency of less than 10 ng/ mL. 2 Other risk factors for vitamin D deficiency include adiposity and female gender.…”

“…2 Other risk factors for vitamin D deficiency include adiposity and female gender. 3,4 The current epidemic of obesity is a challenging public health issue worldwide, 5 and a number of factors may contribute to vitamin D deficiencies in obese children. These include sedentary lifestyles, the prevalence of indoor activities, with resulting decreased sun exposure, and vitamin D sequestration into adipose tissue.…”

“…Less physical activity and dietary habits might explain gender differences. [3][4][5] We conducted a cross-sectional study to measure serum vitamin (35.3%) had vitamin D deficiency, defined as 10-20 ng/mL, and two (2.9%) had a severe vitamin D deficiency of less than 10 ng/ mL. Based on the World Health Organization BMI guidelines, 55 children (80.9%) were of normal weight, three (4.4%) were underweight (BMI < 5th percentile), seven (10.3%) were overweight (BMI of 85th-95th percentile), and three (4.4%) were obese (BMI > 95th percentile).…”

Follow‐up study found that vitamin D deficiency and weight gain increased the risk of impaired fasting glycaemia

“…Obesity‐related consequences, such as type 2 diabetes, cardiovascular disorders and death, have been associated with low vitamin D in adults. However, it is unclear whether vitamin D plays a direct role in glucose metabolism or whether there is an association without direct causality …”

“…However, it is unclear whether vitamin D plays a direct role in glucose metabolism or whether there is an association without direct causality. 1 Longitudinal studies of vitamin D and prediabetes are scarce in children with obesity, and intervention studies in adults have had different follow-up periods. 2 Our original cross-sectional study of children aged 4.5-17.9 years from January 2011 to January 2014 showed that vitamin D deficiency was associated with IFG in children with obesity.…”