Dear Editor,
We applaud the innovative work by Casati et al., which explored the effects of delta-tocotrienol (δ-TT) in promoting osteoblast migration [1]. Vitamin E is reported as a nutrient important for maintaining bone health in epidemiological studies [2]. However, the statement “osteoporosis has been correlated with low intake, and serum levels of TTs” is inaccurate because dietary tocotrienol level has not been shown to correlate with bone health, probably due to the absence of a reliable dietary questionnaire that could assess the tocotrienol intake. Nevertheless, there is an abundance of preclinical evidence on the beneficial skeletal effects of tocotrienol. Most in vitro studies focus on the differentiation of osteoblasts, while the animal studies used bone cellular histomorphometry to quantify the bone cells in osteopenic rats treated with tocotrienol [3,4]. The work by Casati et al. is the first that focuses on the influence of tocotrienol on osteoblast migration, which plays an essential role in fracture healing. More accurately, mesenchymal stem cells migrated to the fracture site during fibrovascular phase and callus formation will differentiate into osteoblasts and perform bone formation [5]. A previous study also showed that particles incorporated with annatto tocotrienol rich in δ-TT could enhance callus strength of male rats with long bone fracture fixed with plate and screws [6]. The finding of δ-TT enhances the transcriptional activities of β-catenin also echoes our previous study, which demonstrated that annatto tocotrienol supplementation (60 mg/kg/day for 2 months) increased beta-catenin gene expression in the bone of orchidectomized rats [7].