Bone weakness can happen after stomach bypass surgery

Q: I had bariatric surgery 3½ years ago and am doing well. I have been faithful in going to my follow-up appointments and take 200 mg of calcium with vitamin D daily. I broke my foot six months ago, and it hasn't healed. What can I do to build back my bones?

A: Your situation is not uncommon after bariatric (weight-loss) surgery. Perhaps you're not getting enough vitamins and minerals to keep your bones strong. Other factors, however, also should be considered.

Bariatric surgery limits the amount of food a person can eat and digest. Three and a half years ago, the most common bariatric operations were gastric banding (lap banding) and gastric bypass (Roux-en-Y). The kind of procedure you had is a factor in determining the amount of supplemental vitamins and minerals needed following surgery.

Both types of surgery limit food intake, but only gastric bypass limits absorption of food, including vitamins and minerals. During gastric banding, the surgeon places a band around the upper part of the stomach, creating a small gastric pouch to receive food. The band limits how much you can eat, and even a small amount of food leaves you feeling full.

In gastric bypass surgery, the surgeon creates a small pouch at the top of the stomach that's sealed off from the rest of the stomach. The surgeon then connects the stomach pouch to the small intestine, which allows food to bypass most of the stomach and the first section of the small intestine. As a result, fewer calories are absorbed from the food ingested.

Gastric banding does not change the body's ability to absorb vitamins and minerals. As a result, impaired bone healing is less likely to occur after that type of surgery. Gastric bypass surgery may affect your body's ability to get enough calcium and vitamin D from food and from the supplements you're taking to keep bones healthy.

In either case, you need a foot X-ray, which should help show why it isn't healing. Second, you should have a bone mineral density test to determine if you have bone loss or osteoporosis - a disease that makes bones thin and fragile, putting them at risk for fracture. Third, your physician should measure your calcium and vitamin D levels, which are important to maintain strong bones.

You have to be careful what kind of calcium supplement you take. The most common supplement is calcium carbonate. To effectively be absorbed into the body, it must be broken down by stomach acid. After gastric bypass, what you eat doesn't pass through as much stomach acid as usual during the digestion process. Most of that acid is made in the larger, bypassed part of the stomach. So you may not be absorbing as much calcium as you think. Instead, you may want to consider another type of calcium supplement, for example, calcium citrate, which can be absorbed even with reduced levels of stomach acid.