I often suggest new users of B12 to do the 5mg daily for 3 months or so. When people finally find us here, they usually have significant pain and issues. If after 3 months, you either get retested, or feel much better, etc, you can cut back to 5mg 2 or 3 times a week, or even go down to 1mg daily --which ever you prefer.

The reason for the loading high dose is because the liver will take up some of the B12 for storage, which is does all the time.
And secondly the B12 needs to move into the brain and that gradient is driven by the amount in the blood. It is an osmotic thing..meaning the more in the blood the more will cross into the brain and spinal cord which need it. Some disease states like MS and Fibro... have been shown to have low B12 in the CNS fluids... so for them they obviously are not getting enough some times. It may be other neurological states, also could be affected and just not discovered yet.

I shall do that, certainly can't hurt anything, plus any benefit derived from vita B-12 will become apparent much sooner. ;)