Vitamin D deficiency in adolescents

Abstract

The prevalence of severe vitamin D deficiency (VDD) in adolescents is variable but considerably high in many countries, especially in Middle-east and Southeast Asia. Different factors attribute to this deficiency including lack of sunlight exposure due to cultural dress codes and veiling or due to pigmented skin, and less time spent outdoors, because of hot weather, and lower vitamin D intake. A potent adaptation process significantly modifies the clinical presentation and therefore clinical presentations may be subtle and go unnoticed, thus making true prevalence studies difficult. Adolescents with severe VDD may present with vague manifestations including pain in weight-bearing joints, back, thighs and/or calves, difficulty in walking and/or climbing stairs, or running and muscle cramps. Adaptation includes increased parathormone (PTH) and deceased insulin-like growth factor-I (IGF-I) secretion. PTH enhances the tubular reabsorption of Ca and stimulates the kidneys to produce 1, 25-(OH) 2D3 that increases intestinal calcium absorption and dissolves the mineralized collagen matrix in bone, causing osteopenia and osteoporosis to provide enough Ca to prevent hypocalcaemia. Decreased insulin like growth factor-I (IGF-I) delays bone growth to economize calcium consumption. Radiological changes are not uncommon and include osteoporosis/osteopenia affecting long bones as well as vertebrae and ribs, bone cysts, decalcification of the metaphysis of the long bones and pseudo fractures. In severe cases pathological fractures and deformities may occur. Vitamin D treatment of adolescents with VDD differs considerably in different studies and proved to be effective in treating all clinical, biochemical, and radiological manifestations. Different treatment regiments for VDD have been discussed and presented in this mini-review for practical use. Adequate vitamin D replacement after treating VDD, improving calcium intake (milk and dairy products), encouraging adequate exposure to the sun and possible enrichment of the stable food with vitamin D in areas with high prevalence of VDD are important measures to prevent the harmful consequences of VDD.

Vitamin D deficiency, bone turnover markers and causative factors among adolescents: a cross-sectional study

“…The prevalence of 25 (OH) vitamin D deficiency in adolescents is different, but considerably high in many regions, like Middle-east and South-East Asia. High prevalence of 25 (OH) vitamin D deficiency in Iran is similar to the results of other studies in Middle East areas, 75.1 % of women and 72.1 % of men in Iran have different level of 25 (OH) vitamin D deficiency [ 4 , 5 ].…”

Vitamin D Deficiency Among Afghan Adolescents in Kabul

“…8,9 Studies conducted in different parts of Pakistan have also shown a high occurrence of hypovitaminosis D. [10][11][12] In India, studies from many parts of the country have also reported a high prevalence of hypovitaminosis D in their youths. 13,14 Vitamin D deficiency is fairly prevalent all over the globe. However, data about vitamin D status among Afghan adolescents is lacking due to scarcity of research on the subject.…”

Prevalence of Vitamin D Deficiency and Calcium Homeostasis in Saudi Children

“…In severe and prolonged deficiency, vertebral compression fractures and fractures of the long bones may occur. Moreover, VDD can be misdiagnosed as fibromyalgia, chronic fatigue syndrome, or simply depression in adolescents (13,36,37). …”