Stress, too much salt and lack of exercise can increase your blood pressure, but now it seems that vitamin D deficiency may have the same effect. Strangely, the phenomenon only seems to occur in Caucasians.
As part of a national health study, American researchers studied 7,699 adults (61% Caucasians and 39% afro-Americans) during the period 1988-1994. They found that Caucasians with sufficient blood levels of vitamin D had a 20 % lower risk of age-related increases in the upper (systolic) blood pressure compared with those who had insufficient vitamin D. A similar link was not seen in afro-Americans. The researchers also noted that 61% of Caucasians and as many as 92% of afro-Americans had insufficient levels of vitamin D, even though vitamin D levels are easy to correct through use of supplements or exposure to sun.
(Source: American Journal of Clinical Nutrition, January 2008)