Calcium and Vitamin D After Bariatric Surgery
By Susan Epstein, MS,RD,CDN
Most people know that calcium is “good for your bones” and protects against Osteoporosis, but how does calcium affect your bones and what role does Vitamin D play? Calcium is very important since it’s basically a “building block” of bone. Calcium plays a role in maintaining bone strength throughout life. However, calcium can only achieve this with the help of Vitamin D. You need Vitamin D to be able to absorb calcium. If a person is consuming enough calcium, but does not have enough Vitamin D, the calcium will not be absorbed. Calcium and Vitamin D work together to protect your bones. People who have had bariatric surgery have a reduced ability to absorb Calcium and Vitamin D. With a reduction in stomach acid, calcium will not be well absorbed. For this reason, the form that calcium comes in is especially important to bariatric patients.
Calcium can be found as Calcium Citrate or Calcium Carbonate. Both are calcium, but are bound to different substances. Calcium Carbonate requires stomach acid to be best digested and absorbed where as Calcium Citrate does not require stomach acid. For this reason, Calcium Citrate is the form of Calcium recommended to bariatric patients. Our bodies cannot absorb more than 500 or 600 mg of Calcium at a time. This is why the recommendation is 500-600 mg twice daily for a total of 1000-1200 mg daily.
As we noted above, Vitamin D helps the body absorb calcium. The main source of Vitamin D is sunlight. As concern for skin cancer from sun exposure has increased, most people have limited their exposure to the sun, which has led to a sharp increase in Vitamin D deficiency. Vitamin D can also be provided through food. Foods, which provide Vitamin D, include, Vitamin D fortified milk, egg yolks, and fatty fish.
To summarize, research has shown that patients who have had bariatric surgery cannot consume adequate Calcium Citrate or Vitamin D through their diet. As a result, supplements are recommended.