Bow-legs

Bone scans were not performed, but typically in osteomalacia there is widespread under mineralization of osteoid, so unlike osteoporosis, osteomalacia is due to poor quality bone causing a loss of rigidity and strength, rather than a quantitative reduction ofbone. A condition in children, which is biochemically similar to osteomalacia, is rickets. Sufferers have misshapen bones of the head, spine and chest and typically bowed legs. 

Bowed legs of middle-aged man with osteomalacia, a nutritional vitamin D deficiency which results in malformation of the skeleton. 

The answer is d. (Murray, pp 627-661. Scriver, pp 3897-3964. Sack, pp 121-138. Wilson, pp 287—320.) People with bowed legs and other bone malformations were quite common in the northeastern United States folio-wing the industrial revolution. This was caused by childhood diets lacking foods "with vitamin D and by minimal exposure to sunlight due to the da-wn-to-dusk working conditions of the textile mills. Vitamin D is essential for the metabolism of calcium and phosphorus. Soft and malformed bones result from its absence. Liver, fish oil, and egg yolks contain vitamin D, and milk is supplemented "with "vitamin D by law. In adults, lack of sunlight and a diet poor in "vitamin D lead to osteomalacia (soft bones). Dark-skinned peoples are more susceptible to "vitamin D deficiency. 

Historically, rickets is a disease of toddlers, especially in northern industrial cities. Their bones are undermineralized, as a result of poor absorption of calcium in the absence of adequate amounts of calcitriol. When the child begins to walk, the long bones of the legs are deformed, leading to bow-legs or knock knees. More seriously. 

Fig. P-28. Rabbit with bowed legs and enlarged joints resulting from eating alfalfa produced on low-phosphorus soils. There is reason to believe that vegetarians on high fiber di may suffer similar consequents. (Courtesy, Washington State University...

Figure 1 This is a typical presentation of a child with rickets. The child is suffering from severe muscle weakness, has bony deformities including bowed legs, and knob-like projects in the middle of his ribcage called the rachitic rosary. (Reproduced with permission from Fraser D and Scriver CR (1979) Disorders associated with hereditary or acquired abnormalities of vitamin D function hereditary disorders associated with vitamin D resistance or defective phosphate metabolism. In De Groot LJ et al. (eds.) Endocrinology, pp. 797-808. New York Grune and Stratton.)...

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