As a bariatric surgery patient, taking vitamin and mineral supplements should be one of your top priorities and is not something that should be taken lightly. After having bariatric surgery, nutrient deficiencies can occur without supplementation as the amount of food you are able to eat will not be enough to provide your body with adequate amounts of the vitamins and minerals it needs. Nutrient deficiencies are serious and can be dangerous. This is why it is important to start a vitamin regimen well before you have surgery, to make sure you are as healthy as possible prior to the procedure.

Your doctor will check your vitamin and mineral levels as part of the pre-surgery work up in an effort to correct any deficiencies you may have. Many people have no idea that they have a vitamin or mineral deficiency because the signs and symptoms can take a long time to develop, and they may be misdiagnosed as something else. It is also not common for doctors to check vitamin levels during regular physicals, unless a patient requests it.

Bariatric surgery involves decreasing the stomach size causing you to eat less. It can also cause the food to bypass certain areas of digestion (depending on which procedure you have) and not all of the nutrients from the food will be absorbed. This means that you MUST take the recommended vitamins and minerals to meet your body’s needs on a daily basis for the rest of your life. It’s not a bad tradeoff when you consider many patients reduce or eliminate medications due to improvements in their chronic conditions!

Shortly after surgery, you will begin with chewable or liquid forms of vitamins and minerals. Eventually, about 1 month later, you can progress to supplement tablets if tolerated or preferred. In the beginning, your stomach can be sensitive to supplements, causing nausea. This is why you never want to take vitamins on an empty stomach! Always take supplements after consuming a meal or protein shake to decrease nausea and improve vitamin absorption.


Research shows that 51% of patients undergoing sleeve gastrectomy had below normal levels of at least one nutrient such as vitamins D, B12, and B6, potassium, iron, or folate1 prior to having surgery. This is why having blood work done ahead of time and beginning to take vitamins is so important, so the deficiencies do not become worse after undergoing surgery.



The typical daily regimen for most patients after surgery includes:

  • Multivitamin
  • 1,000mcg Vitamin B-12
  • 500mg Calcium citrate with vitamin D (2x/day - sleeve) (3x/day – gastric bypass)

The sleeve gastrectomy procedure decreases acid production in the stomach, which can affect iron and vitamin B-12 absorption. This is why it is necessary to take an additional B-12 supplement on top of what is in the multivitamin. Even if you are eating dietary sources that are rich in vitamin B-12, such as fish, beef, poultry, eggs, and dairy, you can still develop a deficiency due to absorption issues.

Despite supplementation, vitamin D deficiency is the most commonly observed deficiency five years postoperatively in sleeve gastrectomy patients. Many bariatric patients struggle with adherence to the vitamin regimen in addition to all the other lifestyle changes involved, as it can be overwhelming to some. This is why we stress getting used to taking vitamins on a regular basis prior to surgery, so that it becomes part of a regular daily routine.

Vitamin D is known as the ‘sunshine vitamin’ because we absorb it through our skin when we are outside in the sun. There are only a few food sources of vitamin D: fatty fish like salmon, egg yolks, liver, and fortified dairy products. Vitamin D deficiency is more likely in people with obesity because of the increased amount of fat cells under the skin, blocking absorption from the sun.


Tips for Proper Vitamin & Mineral Supplementation

  • Set a reminder on your phone. It can be a helpful way to make sure you don’t forget to take them!
  • If they are out of sight, they are out of mind so leave your vitamins out so they are visible and not hidden in a cupboard.
  • Consider purchasing supplements from a bariatric specific vitamin company. They may be slightly more expensive, however, they will better meet your needs postoperatively and they have a wider variety of flavors for chewable supplements.
  • Powdered vitamin/mineral supplements that you add to water are also available if you are having a hard time with chewable supplements.
  • At this time we do not recommend gummy vitamins which can become stuck while swallowing and not contain all the essential nutrients; i.e., thiamin.  Also, we do not recommend the use of transdermal vitamin patches. More research is needed to prove their effectiveness as numerous factors can influence the body’s ability to adequately absorb nutrients from the skin; in addition they are much more expensive than chewable supplements.
  • Vitamin and mineral supplements are not a replacement for nutrient dense foods! Just because you are taking them does not mean you don’t need to focus on eating healthy foods like vegetables, fruits, and lean proteins>
  • It’s very important that you follow-up with your surgeon as scheduled for all of your post-op appointments; not just during the first year after surgery, but once per year thereafter.  There will be designated appointments when labs will be drawn again to check the status of vitamins and minerals.  Based on the titers, the bariatric surgery office clinician will inform you as to whether or not you need to increase or decrease your supplements or keep them the same.
  • Always take only the recommended dosage of vitamin/mineral your bariatric surgeon instructs you to take.  More is not necessarily better, and high levels of certain vitamins/minerals can cause an adverse reaction.  When your titers are elevated, you will be told to stop taking the supplement for a while until your level is back to the normal range.
Carley Baulick MS, RDN, CDN
By Carley Baulick MS, RDN, CDN
Bariatric Dietitian Educator

Carley Baulick, MS, RDN, CDN is Garnet Health Medical Center’s Bariatric Dietitian Educator. She received her Bachelor’s and Master of Science Degrees in Nutrition and Dietetics from the State University of New York College at Oneonta. She is a Certified Dietitian-Nutritionist, holds an Academy of Nutrition and Dietetics Certificate of Training in Adult Weight Management, and is a member of the Academy of Nutrition and Dietetics (AND). Carley is passionate about nutrition and helping others reach their health and wellness goals through individualized counseling and nutrition education. Carley can be reached at (845) 333-2830 or

Read more articles