I wonder whether researchers offer any recommendations based on a difference in effect between ingesting vitamin A and beta-carotene. Do people who consume large amounts of yellow vegetables, for example, put themselves at risk?

Mary A. Turzillo
Berea, Ohio

Yellow fruits and vegetables contain large amounts of the vitamin A precursor beta-carotene. However, says Margo Denke of the University of Texas Southwestern in Dallas, only a fraction of precursors are converted to vitamin A in the body, so eating them is unlikely to cause a vitamin A overdose and weaken bone .–N. Seppa