DEAR DR. BLONZ: How real is the danger from the lead content in calcium supplements? One company promotes its products by saying it contains no lead, but it is unclear how much of an issue this is with other (less expensive) supplements. -- F.R., Phoenix
DEAR F.R.: Some natural sources of calcium do carry a risk of lead contamination when they are used in supplements. These include bone meal, oyster shell and dolomite.
When a body is exposed to heavy metals, such as lead, and if the contaminant is coming in at a greater rate than the body can cast it off, the bones become an inadvertent holding location. As a practical example, animals allowed to graze near sources of industrial pollution can end up with higher-than-normal levels of contaminants in their bones. If these bones are then used to make bone meal for dietary supplements, there is a risk of the unwanted elements ending up in the bottle.
The same argument can be made for oyster shell calcium, if the oysters live in contaminated waters. Dolomite, also called dolomitic limestone, is a mined mineral that's composed primarily of calcium carbonate and magnesium carbonate, plus some other elements. If the mineral happens to be in areas that contain elevated amounts of lead, this natural source could also contain a natural contaminant.
These scenarios do not mean that products made from natural sources will automatically be contaminated. But if you choose a calcium supplement sourced from any of these compounds, you should only select a brand that specifically tests and states that their product is low-lead or lead-free.
DEAR DR. BLONZ: I noticed a bread label that read "stone ground wheat bread," but upon closer inspection, I found it to be white bread with molasses coloring. Is this sort of misleading labeling illegal? -- G.T., Hayward, California
DEAR G.T.: Wheat bread is made with wheat flour, and it can be white, whole-grain or a combination. A 100 percent whole-grain wheat bread tends to tout its "100 percent whole wheat" or "whole wheat flour" content. One of those will be the first item on the ingredient statement and there will be no other flours listed.
All wheat flour is made from ground wheat, and "stone ground" says nothing about any "whole-grain" character of the bread. It is somewhat misleading when a bread that is not whole-grain uses colorants to make it appear as though it is. Molasses can be used to provide some nutrients and help make the bread less crumbly. It is not a legal (regulatory) issue as long as the bread is not claiming or implying that it is whole-grain when it's not.
DEAR DR. BLONZ: Do the X-ray security machines in airports negatively affect the vitamins or medications packed in my luggage? Does it destroy their effectiveness? -- T.T., Boston
DEAR T.T.: There is no evidence of negative effects on dietary supplements or medications from the routine use of security machines in airports.
Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to email@example.com. Due to the volume of mail, personal replies cannot be provided.