Vitamin C not consumed. The time frame for onset of symptoms of scurvy in unstressed adults on a completely vitamin C free diet, however, may range from one month to more than six months, depending on previous loading of vitamin C. Notable human dietary studies of experimentally induced scurvy have been conducted on conscientious objectors during World War II in Britain and on Iowa state prisoners in the late 1960s to the 1980s. These studies both found that all obvious symptoms of scurvy previously induced by an experimental scorbutic diet with extremely low vitamin C content could be completely reversed by additional
Vitamin E E versus placebo. Subset analysis for ischaemic stroke, haemorrhagic stroke, fatal stroke, non-fatal stroke - all no significant difference in risk. Likewise for subset analysis of natural or synthetic vitamin E, or only above or below 300 IU/day, or whether the enrolled people were healthy or considered to be at higher than normal risk. The authors concluded that there was a lack of clinically important benefit of vitamin E supplementation in the prevention of stroke. One large, multi-year study in which post-menopausal women consumed either placebo or 600 IU of natural-sourced vitamin E on alternate days reported no effect on