Taking 0.5g of vitamin C – the equivalent of drinking six glasses of orange juice – every day lowers your blood pressure and reduces the risk of stroke. The amount, which is around five times the recommended daily allowance, is especially effective in people already diagnosed with high blood pressure, or hypertension. The vitamin can lower blood pressure by 5 millimetres of mercury, which is half as good as an ACE inhibitor or diuretic (water pill), in people with hypertension. The immediate impact is a 3 millimetres fall, enough to reduce significantly the number of people who suffer a stroke, say researchers from the Johns Hopkins University School of Medicine. The researchers think the vitamin works in a similar way to a diuretic, allowing the kidneys to remove more sodium and water from the body, and helping relax blood vessel walls. The process suggests that vitamin C doesn’t directly reduce rates of cardiovascular disease, they caution. Vitamin C is found in fruit and vegetables, and can also be taken as supplements. (Source: American Journal of Clinical Nutrition, 2012; 95: 1079-88).