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Creating a Personalized A Gastric Bypass Vitamin Schedule

Creating a Personalized A Gastric Bypass Vitamin Schedule

Nutritional deficiencies are one of the leading risk factors for people who have gastric bypass surgery. Vitamin deficiencies are one of the most common complications after surgery. However, you can avoid this complication with proper vitamin supplementation. You will need to take vitamins for the rest of your life if you have gastric bypass surgery. Here is what you need to know about creating a gastric bypass vitamin schedule.

Why You Need Vitamins and Minerals

Every day, thousands of enzymatic reactions occur within our bodies to maintain homeostasis, communicate between other cells, and support growth and development. Our bodies are continually turning over bone, muscle, blood cells, and skin. To perform all of these processes, we must ingest certain building blocks or raw materials through our diet.

Vitamins and minerals are essential nutrients that help our bodies function. Because we cannot produce our vitamins in most cases, we must get them from our food. Our ability to digest vitamins and minerals depends on an intricate balance within our digestive tract to breakdown and absorb these nutrients.

When something disrupts our ability to properly digest our food, such as an infection or surgery, it can be challenging to get the nutrients we need. Furthermore, severely limiting food intake can also lead to nutrient deficiencies.

Most of our micronutrients come from the food that we eat.

We often classify vitamins and minerals as micronutrients because we only require them in small quantities. On the other hand, macronutrients are nutrients we need in larger quantities and include proteins, carbohydrates, and fats. You probably are already familiar with tracking your macronutrient intake and even water intake through various bariatric diets. However, if you have gastric bypass surgery, you will need to start monitoring your micronutrient intake as well.

Facts About Nutrients Deficiencies After Gastric Bypass

Bariatric surgery patients are far too familiar with the challenges of meeting nutritional needs. Between trying to get enough protein and water intake while not consuming too much at one time, it can be hard to fulfill your body's needs.

Research shows that the number of post-weight loss surgery patients with vitamin deficiencies is on the rise. However, studies conducted by the American Society for Metabolic and Bariatric Surgery (ASMBS) find that bariatric patients are deficient in key vitamins even prior to surgery. Here are some staggering statistics about vitamin deficiency before bariatric surgery.

  • Almost 90% of bariatric patients are deficient in Vitamin D
  • 54% are deficient in folate
  • 45% are deficient in iron
  • 29% are deficient in thiamine
  • 24-28% are deficient in zinc
  • 2-18% are deficient in Vitamin B12 (this may be between 6-30% in patients taking proton pump inhibitors)

With proper nutritional support, these percentages can decrease after bariatric surgery. However, without consistent follow-up with your bariatric surgery team and failing to adhere to a vitamin schedule, your risk for nutrient deficiencies can get even higher after surgery.

Following up with your doctor post-surgery is crucial to help prevent nutrient deficiencies.

Certain weight-loss surgeries can put individuals at greater risk for nutrients deficiencies, especially those that severely alter the digestive tract. Gastric bypass (also known as Roux-en-Y) and duodenal switch procedures are the most complex procedures that change your digestive system.

Here are some leading factors that contribute to nutritional deficiencies in gastric bypass patients:

  • Roux-en-Y surgery "bypasses" a large portion of the stomach and small intestine, which is where the majority of nutrient breakdown and absorption occurs. For example, vitamin B12 is primarily absorbed in the small intestine ileum, but it needs the stomach's acidic environment to break it down. The stomach also releases intrinsic factor, which binds to B12 to be absorbed in the small intestine. Thus, gastric bypass patients are at an increased risk for vitamin B12 deficiency.
  • Gastric bypass alters your gut hormones, affecting everything from how you feel hunger to the way your body digests food. For example, this surgery can change your hormone concentrations in gastrin, ghrelin, and cholecystokinin.
  • Bypassing part of the digestive system can speed up digestion, meaning you have less time to absorb nutrients. A possible complication is dumping syndrome, where your body quickly tries to rid itself of the food you ate.

While gastric bypass may increase your risk for vitamin deficiencies, it is also highly effective at helping people lose a significant amount of weight. And, substantial weight loss can have tremendous benefits for your overall health. Thus, creating a vitamin schedule and sticking to it can increase your chances of not succumbing to vitamin deficiencies after surgery.

All gastric bypass surgery patients will require vitamins for the rest of their life.

Here's What You Need To Include In Your Vitamin Schedule After Gastric Bypass

There are over 30 vitamins and minerals the body needs, making it challenging to figure out what to take and when to take it. Fortunately, most bariatric surgeons will guide you on what vitamins and supplements you need to take. To determine this, you will likely need to regularly follow up with your surgeon for blood work to see if you are at therapeutic levels. However, there are some "standard" doses of vitamins that many gastric bypass patients will need.

The ASMBS recommends the following to prevent post-WLS micronutrient deficiency:

Vitamin B1 (Thiamine) - A minimum of 12 mg daily, preferably a 50 mg daily dose from a B-complex supplement or multivitamin once or twice daily.

Vitamin B12 (Cobalamin) - Dosage depends on what route you take it. Keep in mind that an oral dose may not be feasible for patients with a modified digestive tract like gastric bypass:

  • Oral - 350-500 mcg daily (may be taken as a pill, sublingual tablet, or liquid)
  • Nasal spray - per manufacturers direction
  • Injection - 1000 mcg monthly

Folate (or folic acid) - 400-800 mcg daily in a multivitamin. Women of childbearing age (especially those who are pregnant) will need a higher dose of between 800-1000 mcg.

Iron - Dosage depends on your risk factors and sex. Post-gastric bypass patients require a higher iron dose of at least 45-60 mg of elemental iron each day. Menstruating women may need higher daily doses.

Vitamin D and calcium - Post-gastric bypass patients require between 1200-1500 mg/d of calcium daily. To determine your vitamin D dosage, you will want to have your vitamin D levels checked regularly to ensure you are at a therapeutic level.

You may need to take certain vitamins and minerals separately to ensure maximum absorption.

Vitamin A, E, and K - Dosage depends on your type of WLS surgery. Gastric bypass patients need: Vitamin A = 5,000-10,000 IU/d, Vitamin E = 15 mg/d, Vitamin K = 90-120 ug/d

Zinc: Most of your zinc dose can come from a multivitamin that contains 100-200% of your recommended dietary allowance (RDA) for minerals.

Copper: 200% of the RDA, or 2mg/d

Example of a Gastric Bypass Vitamin Schedule

8:00 AM: Multivitamin with Iron Supplement

11:00 AM: 500 mg of Calcium

1:00 PM: 500 mg of Calcium

4:00 PM: 500 mg of Calcium

7:00 PM: Multivitamin with Iron Supplement

There are over 30 vitamins and minerals the body requires. Fortunately, most can be found in multivitamins.

A Few Tips To Keep In Mind When Creating A Gastric Bypass Vitamin Regimen

Tip #1: There is no one-size-fits-all approach when it comes to a gastric bypass vitamin schedule

Every individual is unique. Therefore, you will need a personalized vitamin regimen to meet your specific nutritional needs. You will want to work with your bariatric surgeon and a nutritionist to ensure you are getting your daily requirements. Your bariatric team will consider your medical history and will monitor blood work.

Tip #2: It takes time to figure out what you need.

Your needs will change with time. Vitamin deficiencies do not appear right away in the post-op period unless you already were deficient. Often, they present over time, meaning that you need to check in on your vitamin levels to meet your body's needs.

Tip #3: Taking too much of a vitamin also has health consequences.

While it may seem like a good idea to load up on the vitamins, you can overdose on your vitamins. If you take slightly over the standard limit, your body will likely rid itself of what it doesn't need. However, if you chronically take too much of a particular micronutrient, it can lead to adverse effects like fatigue and nerve damage.

Every individual will need a personalized vitamin regimen that fits their needs.

Tip #4: You cannot take some vitamins (and medications) together.

Calcium is a micronutrient that interferes with the absorption of other nutrients and medications. For example, you should separate your iron and calcium doses. Similarly, acid-reduction medications often contain calcium, so you will want to avoid taking those medications with your iron supplements as well.

Tip #5: You may need to take your vitamins in divided doses or with food.

You will want to take some supplements at different points in the day to maximize absorption. For example, you should take iron and calcium in divided doses. Additionally, you may need to take certain supplements with meals, like calcium.

Every person needs an individualized gastric bypass vitamin schedule. To make sure you meet your needs, connect with your bariatric surgeon and nutritionist to create a personalized vitamin schedule after gastric bypass.

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Julia Rae Walker, RN, BSN, BA


Julia is an experienced critical care nurse with a background in pediatric and adult patient populations. Her passion is helping patients maximize their quality of life.

Gintas Antanavicius, MD, FACS, FASMBS

Medical Reviewer

Dr. G is a co-founder of BariBuilder. A US-based expert surgeon with over 10 years of bariatric experience, he regularly publishes research in medical journals like SOARD, Obesity Surgery, etc.