Table 5.

Dynamic histology shows vitamin A transiently increases endocortical bone formation after 4 weeks of supplemented vitamin A diet. Histological analysis indicates smaller marrow area and total area after 10 weeks of supplemental diet.

	4 weeks		10 weeks		Interaction
	Control	Supplemented	Control	Supplemented
Periosteal
MS/BS (%)	30.5 ± 2.27	22.0 ± 3.44	31.2 ± 3.85	29.2 ± 1.81	n.s.
MAR (µm/day)	0.72 ± 0.06	0.59 ± 0.07	0.67 ± 0.04	0.64 ± 0.07	n.s.
BFR/BS (µm3/µm2/day)	0.22 ± 0.03	0.19 ± 0.06	0.23 ± 0.04	0.19 ± 0.02	n.s.
Endocortical
MS/BS (%)	76.4 ± 1.40	81.2 ± 2.83	74.0 ± 3.20	81.4 ± 3.38	n.s.
MAR (µm/day)	2.18 ± 0.20	2.82 ± 0.10*	1.38 ± 0.05	1.39 ± 0.11	P < 0.05
BFR/BS (µm3/µm2/day)	1.66 ± 0.15	2.28 ± 0.08**	1.02 ± 0.05	1.16 ± 0.11	P < 0.05
Ma.Ar (mm2)	0.52 ± 0.03	0.55 ± 0.03	0.74 ± 0.03	0.51 ± 0.03***	P < 0.001
Tt.Ar (mm2)	0.96 ± 0.04	0.96 ± 0.04	1.48 ± 0.05	1.2 ± 0.03***	P < 0.01
Ct.Ar (mm2)	0.44 ± 0.01	0.41 ± 0.01	0.74 ± 0.03	0.69 ± 0.01	n.s.

Femur periosteal and endocortical mineralized surface/bone surface (MS/BS), mineral apposition rate (MAR), and bone formation rate/bone surface (BFR/BS) obtained from dynamic histomorphometry, and marrow area (Ma.Ar), total area (Tt.Ar), and cortical bone area (Ct.Ar) after 4 and 10 weeks of supplemented vitamin A diet. Values represented as mean ± s.e.m., n = 10/group, Student’s t-test vs control, 2-way ANOVA for interactions, n.s. indicates no statistical significance.

*P < 0.05, **P < 0.01, ***P < 0.001.