In a study appearing in the journal Hypertension (2007 Mar 19—epublished version), plasma vitamin D (25[OH]D) levels were monitored in a group of 1,811 subjects for four to eight years and another group of 115,919 were monitored for 16-18 years. The researchers found an inverse proportion between vitamin D levels and the occurrence of hypertension. Men with plasma 25(OH)D levels less than 15 ng/mL (vitamin D deficiency) showed more than a six-fold increased risk of hypertension compared to men with 25(OH)D levels at or above 30 ng/mL. Women with vitamin D deficiency had double the risk of being hypertensive. There may well be an association between vitamin D deficiency and high blood pressure.