Depends on your definition of supplements. Say natural and or OTC supplemental it sort of varies from person to person, and no matter what you take if your body fat % is high you will get squat.
http://vascularbodybuildingmuscle.blogspot.com/p/easy-tips-to-increase-your-vascularity.html
Some tips, worth the read.
In the end it is sort of what you said up front, a combo of low body fat, and diet. Agatamine, Citruline, and the like are good, Beta Alanine, NALT & NAC, all help with keeping the blood flowing into the muscle and aid in the pump which in turns tightens things up and if your veins sit close enough they get forced to the surface. But again this all depends on your relative fat %, and if you are hydrated enough. I cannot stress that enough Hydration helps the veins dehydration will cause the veins to flatten out.
Draven whats the story brother just getting into the BBing thing or are you trying to look great shirtless on New Years mate?
Only reason I ask is basically I would not worry about looking a specific way until you have gotten your body to the weight you want it and the BF%. then you can begin the task of shaping and filling in the details like density, striation, separation,fullness, and the road map vascularity; these are all per-contest worries, not really the every day stressers. But if you are trying to look ripped, for a party, there are a few things you can do but really do you want to be that dude that rips his shirt off?
BTW condense with D-POL ( Same Company) with a proper workout will give you a wicked pump and have your veins standing out.( again BF% permitting)
