Vitamins For Gastric Bypass

Gastric bypass is a type of weight-loss surgery in which the surgeon creates a pouch -- about the size of an egg -- with your upper stomach, and connects this pouch to a portion of your small intestines. This allows food to go around, or bypass, the majority of your stomach and a section of your intestines. As a result, your body will not absorb vitamins and minerals as efficiently. Your doctor will likely advise you to take several supplements after having the gastric bypass surgery.

Multivitamins

You should take two daily complete multivitamins that contain 100 percent of the daily value of at least two-thirds of the nutrients on the label. This will ensure you get an overall balance of nutrients. For the first two to three months after surgery, you should plan to take a chewable or liquid multivitamin, as they tend to be easier to digest and absorb. Once you are able to swallow pills with ease, you can switch to a pill form.

Calcium Citrate

Because a part of your intestines is bypassed during this procedure, there is less surface area available for the absorption of some nutrients, including calcium. You will need to take 1,000 to 1,500 mg of calcium citrate daily, and as with multivitamins, you may want to take a chewable or liquid form for the first few months after surgery. Make sure your calcium supplement also contains vitamin D and magnesium to maximize absorption. Do not take calcium carbonate, which is a common supplement form, as it is alkaline-based and, therefore, requires a significant amount of stomach acid to be absorbed. After having gastric bypass, you do not have enough stomach acid in your pouch to absorb the carbonate. Calcium citrate doesn't need as much acid, which is why it is recommended.

Iron

Like calcium, much of the absorption of iron occurs in a section of your intestines that is bypassed with this procedure. However, you probably aren't at risk of iron deficiency, as your body likely has adequate stores. As a result, you may only need iron supplementation if you are a menstruating women or at risk for anemia. If this applies to you, take the equivalent of 50 to 100 mg of elemental iron daily in addition to what is in the two daily complete multivitamins. According to the publication "Surgery for Obesity and Related Diseases," you can take this in the form of ferrous sulfate, fumerate, gluconate, polysaccharide or iron protein succinylate forms.

Vitamin B-12

Vitamin B-12 needs stomach acid to break it down. Because you have less stomach acid after gastric bypass, you are not able to metabolize as much vitamin B-12 from food. You should take an oral supplement of 350 to 500 mcg daily. You can purchase this supplement in the sublingual form, meaning it dissolves under your tongue. Or, you can have weekly or monthly vitamin B-12 injections instead of taking an oral supplement. This is an option, but your doctor must prescribe it.

Tips

To maximize absorption of vitamins, split up the dosage when possible. For example, take 600 mg calcium citrate and one multivitamin in the morning and then again in the evening. Never take iron and calcium in the same sitting as they compete with each other for absorption -- take these supplements at least two hours apart. Because every individual is different in terms of absorption rates of nutrients, your doctor will monitor your blood work regularly to prevent long-term deficiencies and/or toxicities. For example, some people become deficient in thiamine and vitamin D, while others need only a small dosage of the vitamin B-12 supplement. Most surgeons will require that you have your blood drawn two to four months after surgery, and once a year after that.