Has anyone performed a study to look at 25-hydroxy levels in the elderly in each nation? I suspect that is where I would find a difference. Or better, have we

Has anyone performed a study to look at 25-hydroxy levels in the elderly in each nation? I suspect that is where I would find a difference. Or better, have we tested for 1α-hydroxylase to factor in renal function? Obesity is a large contributing factor in the routing and storage of both.