Sounds like something out of a sci-fi movie, but this is done commonly now with certain nutrients. B12 most commonly. There's some buzz about intravenous magnesium sulfate injections as well to increase serum magnesium.
However, now people are able to get a full spectrum of vitamins and minerals into their bloodstream at once. Part of me thinks this is a bit too wild to be used, but in reality it could be considered safe because of the few side-effects of simply having a higher level of certain nutrients in the blood. As long as someone has functional kidneys, it sounds like it's not a high risk medical procedure.
Although it's routine sometimes to receive IV doses of certain nutrients, it's not common for us to simply go in for a nutritional boost in "that way." It might be a good alternative to taking supplements, especially if it's shown to have significant enough benefits.
IV Magnesium sulfate Intravenous magnesium as an adjuvant in acute bronchospasm: a meta-analysis. http://www.ncbi.nlm.nih.gov/pubmed/10969219