Dr Joel Wallach, of Dead Doctor’s Don’t Lie fame, once said that taking vitamins was pretty cheap insurance against disease. This is true, because while vitamins and minerals are often better provided by whole food, they are increasingly absent from the low quality Western diet most individuals consume. However, Wallach also said that vitamin and mineral supplements can only be beneficial as insurance if they are absorbed efficiently from the gut. This is logical because the gut is not part of the internal milieu of the body, and its contents effectively form an outside barrier surface in the same manner as the skin. Therefore just because something is ingested does not mean it will have an effect on metabolic function. To be bioavailable, a nutrient has to be absorbed to the blood and circulated to the cells and tissues upon which it can have a biological effect. A number of factors can influence the bioavailability of nutrients in this way, including the method of delivering that substance to the gut.
Being lipid soluble and present naturally in plant oils, vitamin E is particularly suited to delivery in a softgel. In this way, the oil can be consumed in its native form without chemical processing along with other oils usually present with vitamin E. That softgel vitamin E is better absorbed and tablet or capsule form has been reported in the American Journal of Clinical Nutrition1. In the study, d-α-tocopherol (RRR-α-tocopherol) plasma levels were analysed in 12 healthy subjects after administration of vitamin E preparations in softgels, tablets or capsules (at concentrations of 36.5, 33 and 39 IU vitamin E, respectively). Because vitamin E is an oil and tablets can only be formulated with powder, the vitamin E was in the dl-α-tocopherol acetate form which is dry and and be included in tablets. The acetate moiety is cleaved in the digestive tract and vitamin E released for absorption. The results showed that the vitamin E in softgels was significantly better absorbed when compared to the tablet and capsule forms.
Tablets are manufactured in machines that add binding agents and compress the ingredients creating a solid tablet from powder. This can result in the production of a very hard tablet that may not be accessible to the digestive processes in the gut. In many cases the tablets may pass straight through the digestive tract unabsorbed. Softgels and capsules overcome this problem because they contain the ingredients in an uncompressed form and once the outer layer of the container has been broken down in the gut, the contents are available for absorption. In this study, the vitamin E was in the form of dl-α-tocopherol acetate, which is a powder that is able to be formulated into a tablet. However. addition of the natural oil to softgels may improve bioavailability further because ultimately the vitamin E is absorbed with other lipids in chylomicrons, and being in an oil facilitates this process. Bioavailability is improved further with the d-α-tocopherol form of vitamin E because it is more readily accepted to the tocopherol transfer protein (TTP) in the liver.
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