Q. Is the Daily Value (DV%) for elemental calcium or calcium in combination with other things - like calcium lactate or calcium citrate? Which of these combination forms is best?
A. Leanne Stephens, a dietetic intern at Tufts' Frances Stern Nutrition Center, responds: "Calcium is an essential nutrient that plays an important role in bone health, cardiovascular activity and muscle contraction. Luckily, the Nutrition Facts panels and Supplement Facts panels found on food and supplement packaging, respectively, provide the content of elemental calcium on their labeling. This means that all of the calculations have been completed for you and you just have to look at how many milligrams of calcium are provided in each food or supplement to add up how much you are receiving."
The Daily Value percentages used on these labels are based on 1,000 milligrams of elemental calcium. That may or may not represent the amount you should seek to obtain each day, however, Stephens explains: "The Recommended Dietary Allowances (RDAs) for calcium vary depending on age and gender." For women age 51 and older and men age 71 and up, the RDA is higher than the DV used for percentages on labels - 1,200 milligrams.
"Although it is always best to consume as many calcium-rich food sources as possible, supplementation may be necessary to reach the RDA values," Stephens adds. "Calcium carbonate is the most affordable option, but it can cause stomach and gastrointestinal irritation, so it may need to be taken with food. Calcium lactate and calcium citrate cause less irritation and can be taken with or without food. If you are supplementing a majority of your calcium needs, it may be beneficial to spread your supplement intake throughout the day to maximize absorption and minimize any side effects such as gas or bloating. Talk to your doctor and registered dietitian about your calcium needs."