Table 1.
Summary on the effects of vitamin A and provitamin A on bone health in animals.
| Type of Model | Treatment, Dose, Duration | Findings | Reference |
|---|---|---|---|
| Female C57BL6/J mice (aged 9–19 weeks) | Retinyl acetate (20 µg/g diet; 4 or 10 weeks) | No changes in femur length, tibia length, and BMD at tibia No changes in BV/TV, Tb.N, Tb.Th and Tb.Sp at vertebra No changes in cortical BMC, BMD, Ct.Th, Ec.Pm, Ps.Pm, polar moment of inertia |
[16] |
| Female C57BL6/J mice (aged 9–19 weeks) | Retinyl acetate (60 µg/g diet; 4 or 10 weeks) | No changes in femur length, tibia length, and BMD at tibia No changes in, BV/TV, Tb.N, Tb.Th and Tb.Sp at vertebra ↓ cortical BMC, BMD, Ct.Th, Ec.Pm, Ps.Pm, polar moment of inertia ↓ OCN, ALP at tibial cortical bone ↑ endocortical MAR and BFR ↓ Ma.Ar and Tt.Ar |
|
| Female C57BL6/J mice (n = 10/group; aged 8–9 weeks) | Retinyl acetate (450 µg/g diet; 8 days) | ↓ endocortical circumference, periosteal circumference, cortical BMC, and Ct.Th ↑ Oc.N at periosteum and ↓ Oc.N at endosteum ↑ Acp5, CTSK, RANKL and TRAP in the cortical bone of tibia |
|
| Female C57BL/6N mice subjected to tibia loading (n = 8/group; aged 12–13 weeks) | Retinyl acetate (60 µg/g diet; 4 weeks) | ↓ BV/TV, Tb.N, Ct.Ar, Ma.Ar, Ct.Th, Ec.Pm, Ps.Pm, BFR, MS, and MAR; ↑ Tb.Sp ↓ OSX, ALP, COL1 and no change in sclerostin |
[18] |
| Female C57BL/6N mice subjected to tibia unloading (n = 8/group; aged 12–13 weeks) | Retinyl acetate (60 µg/g diet; 4 weeks) | No changes in BV/TV, Tb.Th, Tb.N, Tb.Sp ↓ Ct.Ar, Ma.Ar, Ec.Pm and Ps.Pm; no change in Ct.Th ↑ BFR, MS and MAR at endocortical but no changes at periosteal No change in OSX, ALP, COL1, and sclerostin |
|
| Mature female Sprague- Dawley rats (n = 45, 15/group, aged 3 months) | Retinyl palmitate and retinyl acetate (600 IU/g diet; 12 weeks) | No change in length of humerus, endocortical circumference and BMD. ↓ humerus diameter, Ps.Pm, total cross-sectional area ↑ serum retinyl esters and total amount of liver retinoid ↓ serum vitamin D and E concentrations |
[19] |
| Female ddY mice subjected to hindlimb unloading (n = 6-8) | β-carotene (0.025%, 3 weeks) | ↑ whole and proximal tibia BMD No changes in minimum and polar moment of inertia of cross-sectional areas. No changes in ALP, OSX, RANKL, OPG, and RANKL/OPG ratio. |
[20] |
List of abbreviations: Acp5: acid phosphatase 5; ALP: alkaline phosphatase; BFR: bone formation rate; BMC: bone mineral content; BMD: bone mineral density; BV/TV: bone volume per tissue volume; COL1: type 1 collagen; Ct.Ar: cortical bone area; CTSK: Cathepsin K; Ct.Th: cortical thickness; Ec.Pm: endocortical perimeters; Ma.Ar: marrow area; MAR: mineral apposition rate; MS: mineralising surface; OCN: osteocalcin; Oc.N: osteoclast number; OPG: osteoprotegerin; OSX: osterix; Ps.Pm: periosteal perimeter; RANKL: receptor activator of nuclear factor-kappa B ligand; Tb.N: trabecular number; Tb.Sp: trabecular separation; Tb.Th: trabecular thickness; TRAP: tatrate-resistant acid phosphatase; Tt.Ar: total area.