 , low Vitamin D levels ( p-value 0.002-0.006, smaller sample, \sim 50 countries  ).
<meaning-changed>  , low Vitamin D levels ( p-value 0.002-0.006, smaller sample, \sim 50 countries  ).
 , low Vitamin D levels ( p-value 0.002-0.006, smaller sample, \sim 50 countries , to be confirmed on a larger sample ).