Fact or Fiction: 'Powder Forms of Vitamin E Don't Work'

Do you feed a powdered Vitamin E supplement to your horse? There is a common belief that powder forms will not meet your horse's needs or raise blood levels - this is not supported by research. Instead, based on the available science, we know this: form of Vitamin E DOES matter, but powder/pellet/liquid isn't a huge factor unless we're comparing to water-soluble/micellized Vitamin E.

So if powder vs liquid isn't the issue, what is? Isomer!

Vitamin E exists is many different structures or 'isomers', which impact bioavailability, because the natural form (d-alpha-tocopherol) is preferentially used by the liver. Researchers have fed powdered forms of both natural Vitamin E (d-alpha-tocopherol) and synthetic (dl-alpha-tocopherol) and reported significant increases in Vitamin E serum levels from both.

In fact, researchers have compared fat-soluble forms of liquid vs powder natural Vitamin E (Fong-Gallagher 2024). The form of vitamin E supplementation did not result in statistically significant differences between the two groups over a period of 10 weeks.

Pagan et al (2011) compared synthetic, water-soluble/micellized & lipid-soluble natural forms of Vitamin E. Both natural forms were more bioavailable than synthetic.

Takeaways ⬇️

• Don't focus on physical form, focus on isomer — natural Vitamin E (d-alpha-tocopherol) is more bioavailable than synthetic forms (dl-alpha-tocopherol) and is more effective at increasing serum levels in deficient horses.

  
  

• For deficient horses, water-soluble forms increase serum levels faster than fat-soluble forms, which is super useful when we need quick increases in serum levels. For instance, if dealing with a neurological case, water-soluble/micellized Vitamin E is recommended, as other forms don't impact cerebrospinal fluid.

  
  

• 🚨 More is not always better! Testing your horse's Vitamin E status and assessing current Vitamin E levels (and sources) in the diet can help you meet your horse's needs without oversupplying nutrients (or blocking the absorption of other vitamins). Work with your horse's healthcare team to identify the best course of action when it comes to supplementing Vitamin E above your horse's base requirement!

If you're not sure if your horse's diet is meeting their base needs, total diet evaluation can help!

Have a myth you want to see fact-checked? Get in touch and I'll add it to the blog list ;)

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Recommended Reading:

Brown, JC., Valberg, SJ., Hogg, M., Finno, CJ. 2017. Effects of feeding two RRR-α-tocopherol formulations on serum, cerebrospinal fluid and muscle α-tocopherol concentrations in horses with subclinical vitamin E deficiency. Equine Veterinary 49(6): 753-758.

Fagan, MM., Adams, A., Harris, P., Krotky, A., Duberstein, KJ. 2019. Cytokine and oxidative stress response to vitamin E supplementation in exercising horses. Journal of Equine Veterinary Science 76(2019): 48-49.

Fagan, MM., Harris, P., Adams, A., Pazdro, R., Krotky, A., Call, J., Duberstein, KJ. 2020. Form of Vitamin E Supplementation Affects Oxidative and Inflammatory Response in Exercising Horses. Journal of Equine Veterinary Science 91(2020): 103103.

Fiorellino, NM., Lamprecht, ED., Williams, CA. 2009. Absorption of Different Oral Formulations of Natural Vitamin E in Horses. Journal of Equine Veterinary Science 29(2): 100-104.

Fong-Gallagher, E. 2024. Comparing the Effectiveness of Different Forms of Vitamin E Supplementation (Liquid vs. Powder) on Serum Alpha-Tocopherol Concentrations in Developing Horses" Honors Scholar Theses. 996. https://digitalcommons.lib.uconn.edu/srhonors_theses/996

Williams, CA., Carlucci, SA. 2006. Oral vitamin E supplementation on oxidative stress, vitamin and antioxidant status in intensely exercised horses. Equine vet J Suppl 36(2006): 617-621.