Fitness Over Forty, a weekly series of video presentations targeting the increasing "over forty" population in East Texas, addresses health and fitness issues that are specific to men and women ages 25 to 54 and older... more »
Dr. David Di Paolo, radiologist at The University of Texas Health Science Center at Tyler and nationally certified fitness trainer, hosts the series featuring UT Health Science Center medical professionals who inform viewers about the benefits of a healthy diet and active lifestyle... more »
Tuesday, March 21, 2006
Calcium is an essential mineral found in many foods, especially dairy foods. Calcium is involved in many body functions, including building and maintaining a healthy skeleton, regulating heart contractions, facilitating nerve conductions, and stimulating hormone release. In nature, calcium exists only in combination with other substances, forming compounds. Several different calcium compounds are used in supplements. These include calcium carbonate, calcium citrate, calcium phosphate, and calcium gluconate.
The human body cannot produce calcium. Therefore, calcium must be taken in as part of the diet. The National Academy of Sciences and the National Osteoporosis Foundation recommend daily calcium intakes of 1000-1200 mg a day for most adult men and women. It would be ideal to consume all of the necessary calcium from the diet. However, most individuals find this difficult to do. Consequently, calcium supplements can be used to fill the gap in dietary calcium intake. It is estimated that the median intake of calcium from food by U.S. adults ranges from 620-760 mg per day.
From a health maintenance standpoint, adequate calcium intakes not only is important for proper bone health, it may lower the risk of colon cancer, reduce cholesterol levels and blood pressure, ease premenstrual symptoms, and aid in weight loss.
In choosing a calcium supplement, be sure to read the label to see the content of elemental calcium in each dose. It is the elemental calcium which is the actual amount of calcium that is in the supplement. Of the most commonly utilized calcium supplements, calcium carbonate is the cheapest. It is also well absorbed. Calcium citrate is well absorbed, and can be taken with or without meals. Calcium gluconate is not as well absorbed as calcium carbonate or calcium citrate. Oyster shell calcium and coral calcium may contain heavy metal contaminants, such as lead or mercury, and should probably be avoided. Coral calcium can also be expensive. There is no "best" calcium supplement for everyone. In selecting a calcium supplement, convenience, cost, availability, and individual tolerance are all factors.
Vitamin D enhances the absorption of calcium. 400 IU/day of vitamin D is recommended. Vitamin K can be found in certain calcium supplement preparations and may be helpful if intake of this vitamin is low. Check with your doctor, however, before taking any sort of vitamin K supplement. There are drug interactions that can occur both related to vitamin K supplementation and calcium supplementation. Such drug interactions that may be considerations when taking a calcium supplement can occur with thyroid hormone, iron supplements, and certain antibiotics, such as levofoxicin, ciprofoxicin. Calcium supplements can reduce the absorption of the antibiotic tetracycline. Calcium may also interfere with iron absorption. If you have any questions about drugs you may be taking and calcium supplements, be sure to speak with your physician or pharmacist.For further information on calcium supplements and the role of calcium in the body, please check out the following links: