Until he gets his D levels up, you can expect any function in the body to be affected.
So any further investigation before this is corrected in his case is rather pointless, to my opinion, unless there's something that is very obvious.
Vitamin D is more like a hormone, it signals 100s of genes which have to do with enzyme activity, biochemical processes, immune function, cell growth . Every cell has receptors for vitamin D, thus the increased need for adequate D3 levels.
50 ng/mL. should be the minimum target range.
Also for proper neurological function, since low vit. D status affects negatively vitamin B12 levels, if he gets this checked, he'll need to do a homocysteine test for neurological B12 (methylocobalamin) and tetrahydrofolate (methylfolate) levels. The standard mma tests won't indicate this.
Cheers.
Niko
Sorry i didn't give you all information. His doctor is very aware what's going on. When he had seizures he sent to hospital immediately they discovered when standing his blood pressure went very low and heart rate increased significantly. A nurologist seen him an said it wasn't epilepsy but did not really know what caused seizures. His vitamin d is extremely low and is on vitamin d at minute. Neurologist said he would see him again in 3 months.
The first person that you need to turn to is your doctor with a list of your husband's symptoms.
I do not understand what you mean when you say your husband has had a few seizures. Have you checked his temperature? When a temperature is high the body can get rigors and start to shake.
If he is unwell to go to the doctor, telephone your surgery to arrange a home visit. Should his condition be bad, you may need to contact the paramedics to come and assess him if he is too unwell to go to the ER.
It is likely that he has some type of infection.
He also may require to have a brain scan done if the seizures are to do with the brain.
Make the telephone call to your doctor or get your husband seen to urgently.