Would I benefit significantly from adding 500 mg of niacinamide (vitamin B3) from BulkSupplements.com to my regimen of supplements, taken twice a week?

This is definitely the case. We have told you previously that the body needs much, much, more of the B vitamins than reflected in the Recommended Daily Allowances by the government regulatory bodies, because those figures are falsely kept low through manipulation, specifically to hinder human well-being.