can bcomplex can raise blood pressure to some individuals?

Answer 1

Yes, the only case I know is of Anaemia, secondary to achlorhydria,(stomach not producing HCl acid) in diabetics taking Glucophage resulting in hypotension. Normalizing of BP resulted, by giving B complex resulted in rise of Hb%.
As a part of that family, thiamin is mainly involved in energy metabolism:turning the foods you eat into a useable energy source for the body, otherwise known as ATP (adenosine triphosphate).

All of the B-vitamins work together to produce ATP, and each different vitamin is also involved in more specific aspects of the human body.

Thiamin helps support healthy nerves and a healthy heart, may positively influence mood, and may also be a useful tool for soothing heartburn.

Answer 2

I have never heard of this as a precaution to taking vitamins.