Table 5.
Effect of dietary silicon on bone health; studies in laboratory animals
| Studies | Methods | Study findings |
|---|---|---|
| Rats | ||
| Low silicon Diets | ||
| Seaborn & Nielsen (95-97) | − Si vs. +Si (25-50 μg/g diet) | ↓: body wt, skeletal Ca, tibial BMD, formation markers, plasma & bone Si |
| Seaborn & Nielsen (98,99) | − Si vs. +Si (10 & 35 μg/g diet) | ↓: body wt, mineral content (femur, tibia & vertebrae), hydroxyproline conent of tibia |
| Nielsen & Poellot (100) | − Si vs. +Si (35 μg/g diet) | ↑: bone resorption |
| Ovariectomy & Si Supplementation | ||
| Hott et al. (101) | OVX + Si (120 μg/kg Bwt) | ↓ osteoclast surface area (SA), ↑ osteoblast SA & MAR, ↓ bone loss, ↑ bone vol |
| Rico et al. (102) | OVX + Si (500 μg/g feed) | ↑: body wt, longitudinal growth of femur, mineral content of femur & 5th vertebrae |
| Calomme et al. (54) | OVX + ch-OSA (1 mg Si/kg Bwt) | ↑: body wt, serum & urine Si, partial increase in BMD at femur and lumbar spine |
| Chickens | ||
| Merkley & Miller (103) | +Si (75 mg/l in drinking water) | stronger tibia & humeri, ↑ ash content of humeri |
| Roland (104) | +Si (0.75% Na aluminosilicate) | ↑ egg production |
| Calomme et al. (105) | +Si (135 mg/kg Bwt/2 d) as ch-OSA | ↑ serum Ca, total BMC (8%), BMD: midshaft (4%), distal metaphysis (5%), hip (6%) |
| Horses | ||
| Nielsen et al. (106) | +Si | ↓ bone related injuries in quarter horses |
| Lang et al. (107) | +Si (0.22 kg/d) | ↑ serum & milk Si levels, ↑osteocalcin, ↓ collagen breakdown |
| Calves | ||
| Calomme & Vanden Berghe (108) | +Si (<5% Si as ch-OSA) | ↑: serum Si, skin hydroxyproline content |
−Si = Si deficient diet; +Si = Si supplementation; OVX = ovariectomy; Bwt = body weight, ch-OSA = choline stabilized orthosilicic acid; BMC = bone mineral content; BMD = bone mineral density; SA= surface area; MAR= mineral apposition rate ↑ = increase; ↓ = decrease