Should an anti-oxidant be present in omega-3 supplements containing DHA/EPA?

Published studies many years ago involved supplementation with DHA//EPA lacking vitamin E (alpha-tocopherol) as an anti-oxidant and comparison to similar intakes of DHA/EPA with anti-oxidant. When the anti-oxidant was absent from the supplements, a moderate depletion in circulating blood levels of alpha-tocopherol was observed and such reductions could be off-set by inclusions of alph-tocopherol in the supplement. Thus, it is standard practice by most manufacturers/suppliers to ensure that appropriate anti-oxidants (such as alpha-tocopherol or other tocopherols as examples) are included in such supplements. Manys supplements contain between 2-10 mg of tocopherols per gram of supplemental oil containing DHA/EPA.