Why You Need Calcium After Bariatric Surgery

As a child, one of the first lessons in nutrition that you likely heard was “drink your milk because it’s good for your bones.” Is there any truth to that nutrition advice? Today we are going to unpack a critical nutrient, calcium, to help you understand what it’s used for in the body!

Calcium is a mineral that is stored primarily in the bones. It is the body’s most abundant mineral and is needed for skeletal structure. Just like all essential nutrients, calcium cannot be produced in the body on its own, and it must be obtained from the food (and supplements) we consume.

How much do I need?

According to published bariatric nutrition guidelines, all patients need to take calcium supplements following surgery. The amount you need will depend on which procedure you’ve had, so be sure to talk to your healthcare provider to ensure you are taking enough to protect your bones. In general, if you’ve had an adjustable gastric band, sleeve gastrectomy, or gastric bypass, you will need 1,200–1,500 mg each day. If you’ve had a biliopancreatic diversion with or without a duodenal switch, you will need 1,800-2,400 mg each day.

Why the divide?

Take in divided doses: You may have heard that you need to split up your calcium, or take it in divided doses. This is very important for optimal calcium absorption as only a certain amount can be absorbed by the body at one time. Current recommendations state to take calcium in doses of 500 mg at a time, spread throughout the day.
Take separately from iron: Another important consideration is to take calcium separately from iron. Iron and calcium compete for absorption in the body—if you take both at the same time, you are putting yourself at risk of becoming deficient in one or both of these critical nutrients.

What happens if I don’t get enough?

It can be challenging for people to take all of the necessary micronutrient supplements following bariatric surgery. However, micronutrient supplementation (and annual follow-up care with your health care provider) is important in allowing you to live your healthiest life possible. Many patients who don’t take their vitamin and mineral supplements as recommended by their health care provider experience the undesired consequences of a micronutrient deficiency.

Current data suggests that patients are at great risk for mineral and bone health issues as they progress from surgery. This is in part due to inadequate intake of or malabsorption of critical nutrients needed to keep bones strong. When you don’t take in enough calcium, the body will pull it out of the bones and send it to other organs that need it to work properly (including the heart, which needs blood levels of calcium to stay in a tight range in order for it to contract—this is why your serum or blood level of calcium will always be normal).

In fact, when people are five or more years out from their bariatric procedures, is when they are at the most risk for bone disorders including multiple fractures due to inadequate bone strength. While the exact reason for this has not been identified, several factors such as hormonal changes, inadequate intake, or compromised nutrient absorption of vitamins A, D, E and K as well as calcium are known to affect bone strength.  One of the longest studies we have to date found that seven years after surgery patients had a three-fold increase in spinal fracture and a five-fold increase in hip fracture compared to same age controls who had not had a bariatric procedure.

What if I don’t like taking big pills?

At Bariatric Advantage we know that the better a supplement tastes, the more likely people are to remember to take it. For this reason, we have developed many chewable options of calcium for you to enjoy! We have eight flavors of soft chews, including our favorite, lemon, as well as lozenges.

Remember, taking calcium every day can have a positive effect on your bone health and help prevent unintended bone loss due to calcium deficiency. Find a product you love and take it every day!


Pizzorno L. Bariatric Surgery: Bad to the Bone, Part 1. Integrative Medicine. 2016;15 (1):48-54.