Scurvy on a diet devoid or nearly devoid of vitamin C, had blood levels of vitamin C too low to be accurately measured when they developed signs of scurvy, and in the Iowa study, at this time were estimated (by labeled vitamin C dilution) to have a body pool of less than 300 mg, with daily turnover of only 2.5 mg/day. The vast majority of animals and plants are able to synthesize vitamin C, through a sequence of enzyme-driven steps, which convert monosaccharides to vitamin C. However, some mammals have lost the ability to synthesize vitamin C, notably simians and tarsiers.
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