Any time your doctor
prescribes a new medicine or supplement for you to take you should always ask about side effects and or benefits to your health. In the case of osteopenia, calcium supplementation is a critical part of the treatment which can delay progression to osteoporosis. Calcium supplementation's effect on blood pressure is an active area of research. Right now there is some evidence that calcium supplements may lower blood pressure by 1-2 mm Hg on average (not proven yet). This means that if your blood pressure was 102/62 before you took calcium, your blood pressure should have dropped to 100/61 on average. This is not a huge drop. It is possible that you are exceptionally sensitive to calcium, but this would be very unusual. As a physician, I don't get worried about a persons blood pressure being too low until the top number is 89 or less or the bottom number is 39 or less, especially if the person has had this blood pressure for many years and they don't have heart disease. It is probably healthier than having a blood pressure of 120/80. At your next visit with your physician, I would bring up these concerns with him or her. Its important for the two of you to be on the same page about your treatment plan. Good luck.