Thursday, March 08, 2012

Vitamin A Question

A reader asked about my article Making It Through the Tough TimesWould a Vitamin A source be needed, and if yes, which one would you suggest?

In the article I outlined the essential basics our horses need to maintain good health. 
Included were:
  • The best hay you can find and afford (grass or mixed)
  • The trace minerals copper and zinc
  • Iodized salt (to provide both salt and iodine)
  • Selenium if you're not in a high selenium area

plus flax and vitamin E when your horse does not have access to growing pasture.

Hay will retain good levels of vitamin A for several months.  In addition, horses store vitamin A in the liver - this is usually sufficient to carry them over the winter until new pasture or spring cuttings of hay are available.  

Once hay is more than six months old, especially in late winter to early spring, you may want to supplement some vitamin A.  In the Arizona regional mixes, vitamin A has been included at a minimum level (15,000 IU) to provide an "insurance" level. 

I like to evaluate the horse's coat condition in the spring to help me decide if I should begin adding some vitamin A until spring forage is available.  If the skin is "scurfy" - dry and flakey with an excess amount of "dandruff" even after a good grooming - I'll add some vitamin A and evaluate for improvement in ten days to two weeks.  Several other things can cause poor coat and skin condition including mineral imbalance, inadequate protein, parasites, illness or dehydration, or can interfere with vitamin A absorption or storage.  But in an otherwise healthy horse I'll expect to see improvement in skin and coat texture.

You can use either beta carotene or "preformed" vitamin A - both are available as human gel-caps from the drug store or from online sources such as  If using beta carotene, look for one that provides a minimum of 25,000 IU of vitamin A activity.  I have used beta carotene with good results but, as horses convert only a portion of the beta carotene to useable vitamin A,   preformed vitamin A will likely give faster results.

If your hay was a late season cutting, deep green and still looks, smells and feels fresh in late winter/early spring and your horse is shedding out to a soft shiny coat with no signs of skin dryness, you probably don't need to add vitamin A.  But if your hay was put up early last summer and your horse's skin and coat are dry and lifeless despite knowing he's getting the essentials, give a couple of weeks of vitamin A a try. 

To learn all the essential requirements your horse should have, consider starting with  Dr. Kellon's NRC Plus nutrition courses.  


  1. Is that a 25,000 IU daily dosage of Vit A?

  2. Hi Pam ~
    Yes, give 25,000 IU per day. If you don't see results in a couple of weeks consider looking at some of the other causes for poor coat condition - hay analysis is a good place to start if you don't do that already.