By Rob Stein, Washington Post Staff Writer
Many Americans, particularly African Americans, may be suffering from unrecognized deficiencies of a key nutrient -- vitamin D -- that increase the risk of bone problems and perhaps a host of other diseases, a growing number of scientists say.
Pediatricians scattered around the country have been surprised to see children suffering from rickets, a bone disorder caused by vitamin D deficiency that had been largely relegated to a bygone era.
