Rat model in palm mixed-tocotrienol or alpha tocopherol challenges previous 2012 Keio University report of bone loss after high intake of vitamin E
A new study has demonstrated that oral administration of high dose of alpha-tocopherol does not cause any significant negative effects on bone mass, bone microarchitecture, bone formation, and bone marrow osteogenic (bone forming) gene expressions. The same is true of mixed-tocotrienol.
In this study, eighteen 10-week male Sprague Dawley rats are divided evenly into three treatment groups: adequate- dietary alpha-tocopherol; high-dietary alpha-tocopherol; and high dietary mixed-tocotrienols per day for 18 weeks.
The substance of study was EVNol 50%, previously known as Tocomin 50%, supplied by ExcelVite.
After the supplementation period, vitamin E concentrations in plasma, liver and bone marrow in rats were measured.
Also examined were bone mass of tibia (bone mineral content, bone area, bone mineral density); bone formation by measuring osteocalcin (serum marker of bone turnover); gene profiling associated to osteogenesis; and bone turnover.
Results revealed high level of plasma and liver alpha-tocopherol as well as gamma-tocopherol concentrations in high-dietary alpha-tocopherol rats.
On the other hand, high dietary mixed-tocotrienols rats showed 10-fold higher tocotrienol concentration of alpha and gamma-tocotrienols in plasma, bone marrow and liver.
Across all three treatment groups, even at such high concentrations of tocopherols and tocotrienols, there is no detection of significant difference in bone mass and bone architecture (tibia epiphysis, metaphysis, lumbar vertebra cancellous bone volume); bone formation (mineralising perimeter, mineral apposition rate, bone formation rate in tibia metaphysis); or bone marrow osteogenic gene expressions.
Chee Yen Lau, Nutritionist of ExcelVite, said:
“These results suggest that a high amount of vitamin E, both alpha tocopherol and mixed tocotrienols), does not pose negative effects on bone mass, bone density and bone structure at an equivalent human daily dose of approximately 390mg and 4,838mg of alpha-tocopherol, and 2,420mg of palm mixed-tocotrienol respectively (human equivalent dose in a 60kg adult).
“These are extremely high daily doses of vitamin E, which generally one is unlikely to consume.”
Lau added that, far from causing harm, researchers from the National University of Malaysia have been studying the effects of vitamin E tocotrienols in relation to bone health.
Published papers from this group have demonstrated that palm mixed-tocotrienol complex confers significant bone protective effects when compared to oestrogen replacement therapy and calcium in ovariectomised rats (postmenopausal osteoporosis models).
These statements have yet to be evaluated by the US Food and Drug Administration.