I have heard that before but it never does anything for me. And my vitamin D is always in the 60 ng per ml range. I will tell you when I lost weight previously my vitamin D level went through the roof... so I wonder if there was confusion on this and people who do lose weight end up with high vitamin D... not that vitamin D causes weight loss.
But high vitamin D is important for so many reasons. I take 5000 IU dot off amazon with K2.