“…The chief cause is probably a reduced dietary intake [Milne et al, 1971], together with an independent effect of ageing on plasma levels [Burr et al, 1974b]. It has been suggested that the prevalence of low levels indicates a widespread vitamin C deficiency and that old people would benefit from receiving vitamin supplements [Franklin, 1963;Read et al, 1965;M ilne et al, 1971;Taylor, 1973], A controlled trial of vitamin C was therefore undertaken in old people with low blood levels, identified by population screening, and their mor tality, morbidity and mental function was observed.…”