Best vitamins after weight loss surgery

Don’t miss these essential vitamins after weight loss surgery!

If you’ve chosen bariatric surgery, it’s important to know how your body’s nutritional needs will change. As Core Specialist Group’s bariatric dietitian, I’m here to help you get the right nutrients for your recovery and long-term well-being.
Author: Amanda Clark
First published:

Best vitamins after weight loss surgery

Why vitamins and minerals are crucial after bariatric surgery

After bariatric surgery, your body becomes like a car with a smaller fuel tank that needs the highest quality fuel to keep it running smoothly. This is where vitamins and minerals come in. They’re the premium fuel that ensures your engine – your body – runs efficiently. Without them, you might face deficiencies that could slow down your recovery and affect your overall health. 

Choosing the best vitamins after weight loss surgery

It’s important to choose supplements that are specifically designed for bariatric patients. These bariatric-specific multivitamins are formulated to meet the unique needs of people who have undergone weight loss surgery. 

“Unlike generic multivitamins, bariatric supplements contain higher doses of certain vitamins and minerals that are often deficient in bariatric patients, such as Vitamin B12 and iron. They are also designed to be more easily absorbed by your changed digestive system.”
Amanda Clark
Bariatric Dietitian for Core Specialist Group

You might wonder if any multivitamin will do the trick. The answer is ‘not really’. While it’s possible to combine various off-the-shelf supplements to meet bariatric needs, I highly recommend using a specific bariatric multivitamin brand. They are designed with your unique requirements in mind and stay updated with the latest research. For example, when new recommendations come in, they adapt their formulations. Generic brands will not do that and don’t cater specifically to bariatric patients. 

If you choose to use a mix of off-the-shelf supplements, it’s crucial to regularly consult with a bariatric dietitian to make sure your regimen covers all your needs.

Essential vitamins and minerals after weight loss surgery

Let’s break down the essential vitamins and minerals you’ll need after surgery. Think of these as the key ingredients in a recipe for a healthier, happier you: 

  • Vitamin B12: Essential for nerve function and blood cell formation. After surgery, your body might struggle to absorb it, so higher doses are necessary.
  • Calcium citrate with Vitamin D: Vital for strong bones. Calcium citrate is easier to absorb post-surgery, and Vitamin D helps your body use calcium effectively.
  • Iron: Critical for making haemoglobin in your blood. Post-surgery, you might not absorb it well, so supplements can prevent anaemia.
  • Vitamin C: Boosts iron absorption and helps with skin health and wound healing.
  • Zinc: Supports your immune system and helps wounds heal, both of which are crucial after surgery.
  • Folic acid: Important for DNA repair and cell growth, which accelerates after surgery.
  • Protein supplements: Help prevent muscle loss and support overall recovery when your food intake is limited.
  • Vitamin A: Necessary for vision, immune function, and skin health.
  • Vitamin E: An antioxidant that protects your cells from damage.
  • Vitamin K: Essential for blood clotting and bone health, especially important if you’ve had a gastric bypass surgery.
  • Thiamine (Vitamin B1): Critical for energy metabolism; deficiencies can lead to serious neurological issues.
  • Omega-3 fatty acids: Good for heart health and reducing inflammation.
  • Probiotics: Keep your gut healthy, which can be disrupted after surgery.

“A well-rounded vitamin regime, including these essential vitamins and minerals, is crucial for maintaining health after weight loss surgery. Each supplement plays a specific role in making sure that your body gets the nutrients it needs to function properly and recover effectively.” 

Amanda Clark
Bariatric Dietitian for Core Specialist Group

Weight loss surgery diet

Adjusting your diet post- weight loss surgery

After surgery, think of your diet as the foundation that supports your overall health. A strong foundation – your diet – supports everything above it (your overall health). Initially, you’ll start with liquids, then move to soft foods, and finally solid foods. Long-term, focus on nutrient-dense foods to make the most of your smaller “fuel tank.” 

Remember this: Bariatric surgery modifies nutrient absorption in two potential ways.

  • Reduced stomach size: This results in less stomach acid, which is needed to make several nutrients more available. Without sufficient stomach acid, you may need different forms of supplements or higher doses. Reduced stomach size also limits the production of a substance in the stomach that helps absorb Vitamin B12. Post-surgery, B12 absorption happens passively and requires higher doses. This is why bariatric multivitamins contain around 500 micrograms of Vitamin B12, compared to about 20 micrograms in typical multivitamins.
  • Bypassed intestine: This occurs in various bypass surgeries but does not apply to sleeve gastrectomy (or gastric banding). A shorter intestine means less time and space for nutrient absorption, leading to some nutrients being malabsorbed.


Given these changes, a bariatric vitamin regimen should be started immediately after weight loss surgery, continue long-term, and be reviewed at least every five years.

“With a smaller stomach and possibly a bypassed portion of the intestine, food intake and nutrient absorption are both impacted. It is, therefore, important to choose nutrient-dense foods to make the best use of your intake.” 

Amanda Clark
Bariatric Dietitian for Core Specialist Group

I recommend three meals and two to three snacks per day to make the best use of your available digestive space while promoting optimal blood sugar and cholesterol control. 

Vital snacks include fruits, nuts, vegetables with dip, dairy foods, and higher protein options. By encouraging long-term protein supplementation, we reduce the pressure on every meal and snack needing to focus solely on protein. This allows for increased fibre and plant-based protective phytonutrients through the intake of fruits and vegetables.

Bariatric surgery and vitamin deficiency

Monitoring and managing deficiencies

Regular check-ups are like routine maintenance for your car. It’s important to have nutritional check-ups at least every six months in the first year after surgery, and then annually. We’ll check levels of key vitamins and minerals to catch any deficiencies early. Common signs to watch for include fatigue, weakness, numbness, and problems with balance and coordination. 

Weight loss surgery vitamins at Core Specialist Group

In summary

Proper nutrition and supplementation are the keys to unlocking your best post-surgery self. By working closely with me and following your tailored diet plan, you can be sure that your body gets everything it needs to thrive. 

Remember, using the best vitamins after weight loss surgery, a nutrient-rich diet, and regular monitoring are your best allies in this journey. Here’s to a healthier, happier you!