Yes I think I'll ask about retesting in a few months, it seems sensible.

The strange thing is not many people got more sun than me last summer, I was out every day and as I was training for a half marathon I was wearing vest/shorts so lots of skin exposure - I still have faint tan lines.

Really out of whack at the moment, running slower, out of breath, taking longer to recover at the end of a run. Falling asleep during daytime. Just hope this supplementation will make a difference.