Hi Nancy!
Some potentially useful info from the Soyfoods Association of North America:
“How does soymilk compare with cow's milk?
Numerous fortified soymilks on the market today contain nutrients in level's similar to cow's milk and are good sources of calcium, vitamin A, riboflavin and phosphorus, as well as many other vitamins and minerals. Most soymilks are fortified with 300-400 milligrams of calcium, 120 IU of vitamin D, 500 mg vitamin A and 3 micrograms vitamin B12 per 8 ounces. Soymilk contains no cholesterol and is low in saturated fat.
Does the calcium absorption differ between soymilk and cow's milk?
While the bioavailability of calcium in soymilk may be slightly less that cow's milk, soymilk is still a significant source of calcium in the diet. In addition, studies have found that in comparison with animal protein, soy protein decreases calcium excretion, presumably due to the lower sulfur amino acid content of soy protein. Consequently, a soy-based diet is able to maintain calcium balance with a lower calcium intake.”
http://www.soyfoods.org/health/faqs.html
Also, I check the Silk site (
http://www.silkissoy.com) and found that they do use calcium carbonate, not calcium chelate:
“Calcium carbonate is a type of calcium that is a naturally occurring mineral found in limestone. We use Calcium Carbonate in our products because it does not adversely interact with other Silk ingredients and has a high bioavailability of calcium. There are 300 mg per 8 oz. serving of Silk Soymilk or 30% of the recommended RDA.
Calcium Chelate is a type of calcium that is surrounded, or protected, by an amino acid. The amino acid protects the calcium from inhibitors like oxalic acid or phytic acid and allows for an improvement in absorption of about 5-10%. It works well as a supplement in pill form and is an option for consumers, but is not stable under processing conditions and is not an option as an ingredient for Silk.”
HTH!