LOW SERUM 25-HYDROXYVITAMIN-D CONCENTRATIONS AND SECONDARY HYPERPARATHYROIDISM IN MIDDLE-AGED WHITE STRICT VEGETARIANS

The vitamin D status of vegetarians was studied in the winter. The gro ups studied were strict vegetarians (G1), lactovegetarians (G2), lacto ovovegetarians eating some fish (G3), and vegetarians who were taking vitamin D supplements or who had been exposed to abundant sunlight dur ing the last 6 mo (G4). A group of healthy women served as control sub jects (C). The serum 25-hydroxyvitamin D [25(OH)D] concentration was s ignificantly lower, the serum intact parathyroid hormone (S-iPTH) conc entration significantly higher, and the dietary vitamin D intake signi ficantly lower in G1 than in C. S-iPTH correlated negatively with seru m 25(OH)D and dietary calcium intake. In conclusion, white strict vege tarians are at risk of vitamin D deficiency, at least in the winter, p rimarily because of a low dietary vitamin D intake, despite a normal s unlight exposure in summer. Low serum 25(OH)D concentrations are accom panied by high S-iPTH concentrations, which also are affected by a low calcium intake. The effect of these changes on bone health remains to be evaluated.