Osteoporosis -- Do I Eat TUMS?

In a previous article, calcium was shown not to be the consideration in the osteoporosis story, that is, increased calcium consumption does not equal increased bone formation. But, we do need some calcium (400-500 mg/day, according to the World Health Organization).

How many times has a patient's lumbar spine been x-rayed where an undissolved calcium tablet traversing its way through the intestine is visualized on the radiograph? Whenever this happens, I ask the patient to bring in their calcium supplements. They invariably return with a calcium carbonate product.

The carbonate form of calcium is commonly found on the market, because it is relatively inexpensive and has a high percentage of calcium per tablet (approximately 40 percent). This is the form found in TUMS and many other less expensive calcium products. It may also be the least absorbable.

There are numerous calcium compounds available including: ascorbate, carbonate, citrate, citrate-malate, dolomite, gluconate, hydroxyapatite, lactate, orotate, and oyster shell. Some vitamin companies claim to have the "most absorbable calcium." This may be overstating what is actually documented in the medical literature and in fact only represents only effective marketing.

There are a handful of research studies comparing one calcium form to another. The following conclusions have been drawn:

citrate absorbs 20-66 percent greater than carbonate¹

citrate absorbs greater than carbonate in achlorhydrics and normochlorhydrics²

absorption as follows: acetate> lactate> gluconate> citrate> carbonate; (all similar to milk-calcium)³

absorption as follows: citrate-malate > citrate or carbonate⁴

citrate absorbs twice as well as hydroxyapatite⁵

citrate-malate absorbs 37 percent better than carbonate in the young and healthy⁶

higher solubility sources absorb 10-44 percent better than low solubility sources⁷

citrate-malate absorbs better than carbonate⁸

hydroxyapatite absorbs better than gluconate^9,10

Calcium is also found in food. This should not be ignored. Bioavailability of calcium from food sources is widely variable as is calcium content.

In the United States, milk is the most recommended calcium source (the wisdom of this is debatable). Calcium absorption from milk has been measured at 27.6 percent¹¹ and 32.1 percent.¹² This compares favorably with spinach, as spinach-calcium absorbs at only 5.1 percent,¹¹ most likely due to the high oxalate count which would bind calcium in the gut. An overlooked calcium source is kale, with calcium absorbs at 40.9 percent.¹² One might anticipate other low-oxalate cabbage family products (broccoli, collards, etc.) to also show good bio-availability of calcium.

The often-rendered advice of this or that calcium supplement, lots of dairy, or TUMs, is at best inadequate. In building a healthy skeleton, calcium is only one of many considerations. Many minerals and vitamins not present in TUMS are vital for bone production and retention.

Alan Cook, DC
Scotts Valley, California