Vitamin E is described as the "lightening rod" of the cell, allowing reactive molecules to strike the cell without damaging it. This is apparent in the case of skin, where vitamin E protects the skin from ultraviolet radiation. Vitamin E-rich foods, when taken, can directly travel to the skin cell membranes and protect the skin.
Vitamin E comes in the form of gels, capsules and oils. Oils and gels can be applied topically to help protect the skin and also for scars. Vitamin E contains alpha-tocopherol, either 100 % pure or mixed. Alpha-tocopherol in its natural form is powdery and thick. Hence, it is mixed with a carrier like olive oil. Vitamin E oil is processed from vegetable oils like corn, soya and canola through vacuum distillation. It is heavy and viscous.
Vitamin E oil has a shelf life of about two to three years. When exposed to air, it reacts with oxygen and hence becomes inactive, resulting in a reduced shelf life and potency. Similarly, exposure to extreme heat also reduces the shelf life. As such, vitamin E oil should be stored under well-protected conditions.
Generally, manufacturers of vitamin E oil add ingredients like glycerides, and therefore, vitamin E content may be in the range of 18-20%. The IU value of the oil (International Units, 100 IU is equal to 67 mg for natural vitamin E and 45 mg for synthetic) may vary from manufacturer to manufacturer, depending on the type of tocopherol present and the percent in the oil. For instance, oil processed from soya will be rich in gamma-tocopherol.
Synthetically produced vitamin E oil comes in the form of esters of tocopherols, mostly acetates and succinates. The esters are more resistant to oxidation during storage than unesterified tocopherols. These are mainly used in pharmaceutical formulations and food formulations to fortify food. They are packed in soft gelatin capsules. The bioavailability of these esterified tocopherols is same as that of unesterified ones and is measured in IU.
ไม่มีความคิดเห็น:
แสดงความคิดเห็น