Wylie* Although I have never personally used B-6 for weight loss and I'm certainly no expert, I believe it is used to relieve symptoms of edema and to help those with problems with water retention, which may be why you are seeing weight loss.
People who are deficient in B-6 may show signs of depression and it's also used to balance hormones I think, which may explain why it benefited you with ppd.
But, that said, always check with your physician for the best advice.
Reached 30 lb. Weight Loss Goal April, 2010
Fighting The Battle to Maintain