Recommended intake of vitamin D2 is not as effective as vitamin D3 in recovering serum 25OHD in vitamin D insufficient Sham and OVX rats.

GONZALES CHAVES M; MAROTTE C; PELLEGRINI G; BRYK GABRIEL; FRIEDMAN S; ZENI SN

Toronto,

Congreso; American Society for bone and mineral research; 2010

ASBMR

According to previous works, D3 is almost twice more potent than D2 in raising 25OHD levels (J Clin Met endoc 93:3015, 2008). We performed a study using our model of vit D insufficiency (Bone 39: 837-844, 2006) in adult SHAM and OVX rats re-fed 2 different isocaloric diets, both supplying the recommended dietary vitamin D intake but differing in the source of vit D During 15 days post-surgery all rats were fed a diet containing 15% protein, 200IU% vit D and 0.6% calcium, followed by an additional period of 45 days on a diet lacking vit D (0 IU%) to obtain vit D insufficiency. After the105-days, the rats were divided into 4 groups and fed a diet containing 100IU% of D2 (OVX+D2 and SHAM+D2) or D3 (OVX+D3 and SHAM+D3). Baseline, 60, 85 and 105 days serum 25HOD (ng/ml) levels were measured in each group using a methodology that recognizes both 25OHD3 and 25OHD2 (125I RIA Kit, DiaSorin, Stillwater, MN, USA). Results of SHAM and OVX rats are shown in figures 1 and 2, respectively.   (*) p< 0.01 compared to baseline and (**) p<0.05 compared to D2 Conclusions: Under our experimental conditions, recommended dietary intake of vitamin D supplied by adding D3 to the diet is more effective than supplying D2 in raising 25OHD levels during a 45 day period in both estrogen conditions. PIP 6483