Low dietary silicon supplementation effects on bone and cartilage

Silica is recognized as a necessary nutrient with positive effects on bone and cartilage growth and metabolism. Deficiency can lead to disease of these structures. As a result a number of supplements for both humans and horses and arisen to address this. However dietary supplementation of healthy horses that demonstrate positive clinical effects are not to be found. Too make this a bit more difficult excessive dietary silicon has been associated with some health risks. In spite of this ingested silica is safe at anything approaching reasonable levels. Here we see 300 mg supplement (silica content?) per 220 lb of horse daily. This was on top of what ever exposure the horse got through its food. Supplementation at this rate had no effect over almost 3 months. The authors go on to suggest that there is some level of supplementation that may help bone and joints but that level has yet to be determined.
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Low dietary silicon supplementation may not affect bone and cartilage in mature, sedentary horses
J Anim Sci. 2020 Nov 20;skaa377. doi: 10.1093/jas/skaa377. Online ahead of print.
Authors
Abby Pritchard 1 , Brian D Nielsen 1 , Cara Robison 1 , Jane M Manfredi 2
Affiliations

1 Department of Animal Science, College of Agriculture and Natural Resources, Michigan State University.
2 Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University.

Abstract

As osteoarthritis is a major cause of lameness in horses in the United States, improving collagen health prior to onset and increasing collagen turnover within affected joints could improve health- and welfare-related outcomes. Through its positive effects on bone mineral content and density and its role in increasing collagen synthesis, silicon (Si) may slow the development and progression of osteoarthritis, thereby reducing lameness. This study evaluated the hypothesis that Si supplementation would increase cartilage turnover through increased collagen degradation and formation markers, as well as bone formation markers, resulting in reduced lameness severity as compared to controls. Ten mature Standardbred geldings were assigned to either a treated (SIL) or control (Con) group and group-housed on pasture for 84 d. Horses were individually fed to ensure no cross-contamination of Si other than what was present in the environment. For the duration of the study, SIL horses received a Si-collagen supplement at the rate of 0.3 g supplement/(100 kg bodyweight∙day). Serum samples were taken weekly for osteocalcin, and plasma samples were taken on d 0, 42, and 84 for plasma minerals. On d 0, 42, and 84, subjective and objective lameness exams were performed, and radiographs and synovial fluid samples were taken from reference and osteoarthritic joints. Plasma minerals were similar in both groups and were lower on d 84 than d 0 (P < 0.05). Silicon supplementation, fed at the manufacturer's recommended rate, did not improve lameness or radiographs as compared to controls, and supplemented horses did not show greater collagen degradation and/or synthesis markers in synovial fluid than controls, indicating that cartilage turnover remained unaffected. However, a minimum beneficial threshold and range for Si supplementation standardized to bodyweight need to be established.