Source of vitamin D?

[JillA]

I am following up another line from Jenny Paterson's visit, that without vitamin D some horses can't absorb enough calcium and one of the symptoms of insufficient calcium is skin itching/irritation. Sunlight on skin is the best, but when you have a horse who has to be rugged and is dark in colour and is itchy it is worth looking at supplementation. So.............I have asked and googled and so far all I have come up with is cod liver oil (which also has high vitamin A which counteracts the D anyway) or Brewers yeast which someone mentioned but I can't find any evidence that it does contain Vitamin D. Anyone know/can direct me to that evidence or can suggest an alternative source?

 

[khalswitz]

Best source (if horse is dark skinned and rugged therefore not getting enough sunlight) is fresh grass, which contains good level of the plant based D2. Hay doesn't - d2 is less stable than d3 (found in animals and what you get in milk etc) so doesn't survive the conservation process.

Most feeds don't seem to have additional vit d, but if you must have a supp over grass then try something fungus based - there is one for people that is safe to feed to horses made from mushrooms but I can't remember the name.

Just be aware that excess vit d has the same symptoms as deficiency, so it can be hard to tell.

 

[JillA]

Thanks - that is interesting about the mushrooms, just recently someone I know old me she was involved with getting a mushroom preparation to market. (Horse concerned is on a minimal grass diet as he reacts badly to summer grass. Vit D deficiency is something you never consider - how about all those laminitic ponies on permanent box rest??)

 

[Archangel]

Linseed is a source of vitamin d (though not a huge amount) and great for the skin too.

 

[khalswitz]

Thanks - that is interesting about the mushrooms, just recently someone I know old me she was involved with getting a mushroom preparation to market. (Horse concerned is on a minimal grass diet as he reacts badly to summer grass. Vit D deficiency is something you never consider - how about all those laminitic ponies on permanent box rest??)

Yeah, it's not something you really think about - but like you say, laminitics on permanent box rest, or I'm sure I remember a study saying that latitudes over 34 degrees mean the angle of sunlight doesn't absorb sufficiently through the skin...

You do get Vit D fortified omega oils, which could be worth a try, but with Vit D sups you have to watch you don't end up feeding animals products to your horse as usually D2 (the plant version) doesn't last very well so animal D3 is used instead.

 

[Slightlyconfused]

we have used this with success in the past

http://www.supplementsolutions.co.uk/equine/horse-first-omega-d-oil-2-litre-equine.html

 

[Tnavas]

Vitamin D deficiency is not something you need to worry too much about as the horse will metabolise much of what it needs when exposed to the sun. Excess is stored for use through the winter.

If your horse eats sun dried hay it will also be getting vitamin D. Cod Liver Oil has traditionally been the source of Vitamin D for many stabled horses. Yeast is also a good source, probably the fungus that someone earlier mentioned.

Be aware that overdosing Vitamin D produces similar symptoms as under dosing.

If you think your horse is deficient get your. Horse and forage tested.

Vitamin D is an oil based vitamin so is stored in the body.

 

[khalswitz]

If your horse eats sun dried hay it will also be getting vitamin D.

This is true, although soaking hay for laminitics will leach much of this out. I agree with Tnavas that is you *do* think you have a deficiency, get your horse tested as well as your forage before upping amounts, as very little excess is required for toxicity.

Yeast a good option AS LONG as it has been UV treated.