1790
Investigation into scurvy by James Lind resulted in the inclusion of citrus juice in the rations of sailors in the British Navy. Although the effectiveness of citrus fruits and fresh vegetables as a cure for the disease had been reported on occasions throughout the seventeenth century, it was not until the 1790's that this became British Navy policy.
Harper, A.E. (2000) Recommended Dietary Allowances and Dietary Guidance. Cambridge World History of Food. Cambridge University Press.