I use the spray as I was too scared to take the pills as I read bad things about side effects and I'm a coward.
I had a massive problem this year with vitamin D after being given 40000 units 4 times, I really suffered I have since learnt that vitamin D depletes magnesium and that might be why I reacted so badly. In the US they always take Vitamin D, vitamin k2 and magensium together for this reason, docs don't tell us that here though.
I believe it has helped my sleep and I've taken to rubbing it on achey bits after reading reviews but I don't know if it really helps them.