Research appearing in the Archives of Internal Medicine (2005;165:1246-1252), suggests that there may be a connection between low levels of vitamin D and calcium, and PMS. Earlier studies have shown that the blood levels of vitamin D and calcium were lower in women with PMS than in women without PMS. This study surveyed the dietary intake of over 3000 women between the ages of 27 and 44. All women were free of PMS at the start of the study in 1991. During the course of the study, over 1000 of the women remained free of PMS and more than 1900 of the women developed PMS. Intake of vitamin D and calcium was determined by food frequency questionnaires given in 1991, 1995 and in 1999. Higher intake of vitamin D and calcium was associated with a lower incidence of PMS.