d.There is an increasing awareness of a preclinical phase of vitamin D deficiency, i.e. vitamin D insufficiency,24,37 which increases the risk of osteoporotic fractures in adults.38,39 This term describes biochemical evidence of deficiency [serum 25-hydroxy vitamin D level < 20 ng/mL] without obvious clinical signs or symptoms, such as radiographic osteopenia.40 There is growing evidence that vita