Vitamin C megadosage the airways as a result of vigorous exercise. EIB seems to be caused by the loss of water caused by increased ventilation, which may lead to the release of mediators such as histamine, prostaglandins and leukotrienes, all of which cause bronchoconstriction. Vitamin C participates in the metabolism of these mediators and might thereby influence EIB. A meta-analysis showed that 0.5 to 2 g/day of vitamin C before exercise decreased EIB by half. A meta-analysis showed a significant positive effect of vitamin C on endothelial function. Benefit was found of vitamin C in doses in the range from 0.5 to 4
The Vitamin Shoppe 2015 study, led by Dr. Pieter A. Cohen of Harvard, found that three supplements — JetFuel Superburn, JetFuel T-300 and MX-LS7 — sold at Vitamin Shoppe contained BMPEA. In response, Vitamin Shoppe removed these products from shelves because the safety of these supplements were in question and may not comply with F.D.A. regulations. On January 19, 2007, independent laboratory ConsumerLab.com found 32.8 micrograms of lead per daily serving in Vitamin Shoppe's "Especially for Women" multivitamin. 15.3 micrograms is more than ten times the amount of lead permitted without a warning label in California, the only state to regulate lead in