chapter  11
22 Pages

Vitamin A and Bone

In 1998, we reported that intake of vitamin A at levels only slightly greater than the recommended daily intake was associated with reduced bone density and increased risk of hip fractures (Melhus et al., 1998). The study was prompted by consistent animal and in vitro data, reports on osteoporosis as a toxic effect of long-term therapy with synthetic retinoids, and the observation that Sweden and Norway, for unknown reasons, have the world’s highest incidence of osteoporotic fractures and that the vitamin A intake in these countries is unusually high due to a high consumption of forti„ed milk products, cod liver oil, and multivitamins (Melhus et al., 1998).