has anyone had a horse suffer from a Vitamin d deficiency. With the rise in rugging and the grey wet weather I wondered if the fortified feeds kept this at bay or if it was common. I had a horse 50 years ago that suffered symptoms very like chronic grass sickness, unable to eat, tremors and patchy sweating and serious weight loss. The vet said it was Vitamin d deficiency due to wearing rugs and the short days in the north of Scotland I wondered now if in fact he was suffering from grass sickness he made a full recovery so perhaps not