This question is probably best for Mark. But figured i would post for all in case others also wonder about how much is too much B vitamins. I bought a time released extra strength high potency B complex. the ingredients are as follows:
Vit B1 150mg 10,000%
Vit B2 150mg 8,000 %
Niacin 150 mg 750%
Vitamin B6 150 mg 7,500%
folic acid 800 mcg 200%
vitamin b12 (cyanocobalamin) 160mcg 2,667%
biotin 160mcg 53%
Pantothenic acid 150mg 1500%
Choline 150mg
Inositol 100mg
PABA 25 mcg
GABA 200mg
Are these doses too high or is it appropriate because not all of these vitamins absorb as easily as the IV forms? Is there a chance of toxicity with this preparation or side effects i should be aware of?

The good news is that B vitamins are water soluble, so anything your body can't use will be excreted in your urine. High doses can make your pee turn a very vivid neon shade of yellow, so don't be alarmed if that happens! I don't know what the recommended doses for concussion or headaches are, though.

It is really not recommended to take more than 100mg of B6 a day. I typically recommend 50mg a day.

B6 is stored, in muscle and liver for a short time. And B12 is also stored for up to 5 yrs in the liver.

Too much B6 daily can lead to toxic neuropathies, but that is not common. The other B's in that product are not problematic as far as I know.

Looks good to me. I take a combined 300 mgs of B-6 and 380 mcg of B-12 and my doctor likes my blood lab results. My B-12 is right where it should be.

I have been taking these levels of B's for a decade or more. An MD doctor got me started back in 1982.

Vitamin C will give you neon yellow urine. It just means your body jas enough and is excreting the rest.