Make the Most of Your Calcium Intake

What you need to know about calcium

• Recommended daily intake of calcium is 1200 mg for women over 50.  This should be roughly ½ from diet and ½ from supplements.
• You can only absorb 500 mg of calcium at a time.
• Calcium supplements require stomach acid to dissolve, so they should be taken with a meal.  The food stimulates secretion of acid.  The exception:  calcium citrate dissolves without acid.
• Once dissolved, a small amount of calcium can be absorbed in the intestine alone, but vitamin D is required for calcium to be actively absorbed in useful quantities.
• Calcium and D are necessary, but not sufficient for best bone health.  The two alone may increase bone density, but at best really just reduce the rate of bone loss.  The recommended daily dose is 2,000 IU of vitamin D3.  Some people absorb D better than others; a blood test to check for adequate D levels is recommended.
• Accelerated bone loss among women during the peri-menopausal period occurs between the ages of 40 to 54 years, and then stabilizes.  A second period of accelerated bone loss begins at age 70 among women, notably in the total hip, which can lead to a substantial drop in bone density and strength by age 75 years.  This loss is associated with the increased incidence of hip fractures. 
• If your calcium intake is less than your body needs, parathyroid glands imbedded in the thyroid gland are activated to produce parathormone (PTH).  This hormone stimulates osteoclasts to breakdown bone in order to release calcium.  Blood levels of calcium are maintained in a narrow normal range, and bone reserve is tapped when levels fall at the expense of bone density.  
•  Use of potent meds to control acid reflux or gastritis such a Prilosec (omeprazole) interferes with calcium dissolution and absorption contributing to low blood levels of calcium.