A new study affirms that alpha-tocopherol does not interfere with tocotrienol uptake and distribution, and improves the uptake of tocotrienols.
 
Conducted at Iowa State University, the trial (Hansen H., et al., 2015) evaluated the distribution of vitamin E isoforms (tocopherol and tocotrienol) in laying hens. The study showed that the presence of alpha-tocopherol improved the uptake and enhanced the distribution of gamma- and delta-tocotrienols in certain tissues and organs. It also demonstrated the poor uptake of annatto tocotrienol (tocopherol-free tocotrienol) as more than 90% of the tocotrienols are excreted.
 
Vitamin E family comprises eight chemically distinct compounds – four tocopherols and four tocotrienols (alpha-, beta-, gamma-, and delta- respectively). Alpha-tocopherol has been documented to be more bioavailable due to its strong binding affinity to alpha-tocopherol transfer proteins (alpha-TTP) in the liver. It was once thought that the presence of alpha-tocopherol is believed to exhibit bio-discrimination against other vitamin E forms, including tocotrienols. Hence, tocotrienols were mistakenly thought to be poorly absorbed in the presence of alpha-tocopherol.
 
In this tissue distribution study, alpha-tocopherol and tocotrienol preparation shows higher gamma-tocotrienol level in the liver, kidney and brain; while the distribution of delta-tocotrienol was higher in almost all the tissues tested (e.g. fat pad, liver, brain, oviduct, yolk, breast and thigh meat), compared to the tocopherol-free tocotrienol preparation (better known as Annatto Tocotrienol); suggesting that alpha-tocopherol facilitates the uptake and distribution of tocotrienols into tissues and organs.
 
In addition, the study reported that more than 90% of annatto gamma- and delta-tocotrienol intake was found in the manure, indicating that less than 10% had been absorbed. This corresponded to the finding in humans where pharmacokinetic study showed gamma- and delta-tocotrienol were poorly absorbed. The absolute absorption rate for gamma- and delta-tocotrienol is approximately 9.1% and 8.5% respectively (Yap SP, et al., 2001).
 
The results from this particular study compliment two other earlier studies conducted at the Ohio State University Medical Center that showed tocotrienols are well-absorbed in alpha-TTP knock-out mice (Khanna S, et al., 2005) and in human tissue distribution study (Patel V, et al., 2012) where the tocotrienols are absorbed and deposited in vital human organs in the presence of alpha-tocopherol.
 
For more information: www.excelvite.com; www.tocotrienol.org