Feed Materials In Focus – Vitamin E Supplements for Muscle Support Reviewed.


We have been getting quite a few messages from owners asking about the best Vitamin E supplements for PSSM, RER, tying-up, sore muscle prone horses and as always we are a member led site and so David has reviewed this for you!


Synthetic – Cheap, less effective at raising plasma or muscle levels, less biologically active e.g. all-rac-alpha-tocopherol acetate, DL-α-tocopherol Acetate

Natural – More expensive, more biologically active, more effective at raising plasma or muscle levels e.g. RRR alpha-tocopherol


Some manufacturers list mg instead of IU. 

To convert from mg to IU:

1 mg of alpha-tocopherol is equivalent to 1.49 IU of the natural form or 2.22 IU of the synthetic form.

To convert from IU to mg:

1 IU of the natural form is equivalent to 0.67 mg of alpha-tocopherol.

1 IU of the synthetic form is equivalent to 0.45 mg of alpha-tocopherol.


A muscle support should contain around 1mg per day selenium.

Inorganic selenium – Cheap, has a very low safety margin e.g. sodium selenite

Organic selenium – From yeast, more expensive e.g. selenised yeast


For a 500kg horse a suitable daily dose would be around 3000IU (Natural Vitamin E).


About Author

Dr David Marlin is a physiologist and biochemist who has worked in academia, research and professional sport. He has worked in the equestrian and veterinary world and in human sport, healthcare, medicine and exercise science. In 1989 David obtained his PhD from the UK’s leading sports university, Loughborough University following a four-year study on the responses of Thoroughbred racehorses to exercise and training, undertaken at the renowned Animal Health Trust in Newmarket. You can read David's full biography in the Our Website section.