Bariatric Surgery and Vitamin B12, what do I need to know?


Vitamin B12 deficiency can be a complication after bariatric surgery.

Malabsorptive surgeries such as the gastric bypass and the duodenal switch (rarely performed in the UK) are at higher risk of deficiency.

Vitamin B12 is often prescribed after bariatric surgery to prevent deficiency.

Vitamin B12 is absorbed in the small intestine. The lining of the mouth is also capable of absorbing vitamin B12 from food, but it is a small insignificant amount.

The stomach produces a glycoprotein called intrinsic factor which is essential for the absorption of vitamin B12 in the small intestine.

Why is vitamin B12 needed?

Vitamin B12 helps keep the body’s nervous system and blood cells healthy. Vitamin B12 also helps prevent megaloblastic anaemia.

Deficiency of vitamin B12 occur after bariatric surgery

Bariatric surgeries either reduce the size of the stomach or lessen the absorption of nutrients or both.

In Gastric Sleeve surgery the reduced size of the stomach results in a decrease in ghrelin (the hunger hormone) and reduced food intake.

There is also reduced production of an intrinsic factor which is needed for vitamin B12 absorption.

In Gastric Bypass surgery, the part of the stomach where the intrinsic factor is produced is avoided and never exposed to food.

When does deficiency of vitamin B12 occur?

The liver can store up to 3 years requirement of vitamin B12, so deficiency does not usually happen early after bariatric surgery.

Studies show that a significant number of patients become symptomatic within 1-2 years of gastric bypass surgery if not supplemented with Vitamin B12. Vitamin B12 injections are usually prescribed every 3 months for life following Bariatric Surgery. There are other forms of vitamin B12 available (sub lingual and nasal spray.) You should discuss this with your bariatric surgeon or bariatric dietitian.


Signs and Symptoms of vitamin B12 deficiency:


  • Feeling Weak
  • Fatigue
  • Dizziness
  • Loss of appetite
  • Diarrhoea
  • Painful swollen tongue
  • Pins and Needle sensations in the hands and feet
  • Nerve damage
  • Abnormal heart function
  • Poor Memory


Vitamin B12 supplementation is important after bariatric surgery, especially those patients who have had Gastric bypass surgery.

Obesity: What are my options?

Obesity, its causes and treatment options:

Obesity and its related health conditions are now considered as the world’s biggest health problem.

What are the causes of obesity and how it could be prevented or treated?

Excess weight is mainly due to what we eat and our lifestyle choices. However, some people are at a disadvantage as overeating can be driven by biological factors, genetics and hormones. Some people have a predisposition to gaining weight.

These people can overcome these disadvantages, but it requires modification of eating behaviour and lifestyle changes in the long term and is easier said than done.


Some people seem to be genetically susceptible to obesity. Children of obese parents are much more likely to become obese than children of healthy weight parents. Is this nature or nurture?

Insulin resistance

Insulin is a hormone that regulates energy storage. Elevated insulin levels cause energy to be stored in fat cells instead of being available to use. Elevated insulin levels can lead to insulin resistance

The Western diet promotes insulin resistance which is linked to developing obesity and this contributes to the development of Type 2 Diabetes.

To lower insulin levels, cut back on refined carbohydrates and sugars, combined with increasing fibre intake and activity levels, which will also lead to a decrease in weight and reduction in the risk of developing Type 2 Diabetes.

Leptin Resistance

The hormone Leptin is produced by fat cells and the amount in the blood increases with a higher body fat mass. As a result, leptin levels are high in people with obesity.

In people with a healthy weight, high leptin levels reduce appetite.

In some obese people, the brain does not respond to Leptin, so they keep eating which causes fat cells to produce even more Leptin. This is known as Leptin resistance and the Leptin levels will keep increasing as a person gets fatter.

Underactive Thyroid

This is a condition where the thyroid gland does not produce enough thyroid hormone. This deficiency of thyroid hormone can disrupt the heart rate, body temperature and metabolism.

Symptoms include fatigue, cold sensitivity, constipation, dry skin, depression and unexplained weight gain.

Blood tests can diagnose an underactive thyroid.

Treatment generally involves taking the oral medication Levothyroxine. Levothyroxine is usually continued for life and can reverse the symptoms and help you to return to a healthier weight.


Some prescribed drugs can cause weight gain as a side effect. These drugs alter the function of your body and brain, reducing metabolic rate (reducing calories burned) or increasing appetite resulting in weight gain.

Steroids, also known as corticosteroids, used to treat conditions such as arthritis and asthma increase the appetite in some people, which leads to weight gain.

Cushing Syndrome:

A very rare syndrome affecting less than 1 in 50,000 people is caused by high levels of cortisone in the body. Weight gain is a common symptom, particularly on the chest, face and stomach.

Processed foods and addiction

Processed foods are usually full of cheap refined ingredients and additives which promote overeating, lack of satiety and addiction.

Many high-fat and sugary junk foods stimulate the reward centres in the brain.

Some people become addicted to these foods, the same way someone would become addicted to alcohol or drugs.

The brain chemistry changes and addiction are difficult to overcome.

As processed junk food is available everywhere, in some poorer neighbourhoods it can be difficult to source healthy foods locally.


Added sugar is probably the single worst aspect of the modern diet. Sugar changes the hormones and biochemistry of your body when consumed in excess, leading to insulin resistance.

Excessive sugar intake is considered to be one of the main causes of obesity.



The food industry

Food marketing is unethical at times and unhealthy foods can be marketed as healthy foods and sadly, this is often targeted at children. Many of today’s children are becoming obese and addicted to junk foods before they are even able to make their own choices.

It is easy to use the above reasons as excuses not to aim for a healthier lifestyle and healthier weight.

Emotional eating:

Unfortunately, often the body’s natural response to uncomfortable emotions is to reach for food as comfort. This is usually foods high in sugar and fat as these foods very temporarily give a boost in feelings of wellbeing. Food can and does temporarily fill an emotional void.

Often with professional help it is possible to find ways of dealing with emotions in a way that does not include food. Whether this is to help to change habits, to deal with stress, anxiety, depression and past traumas etc., qualified professionals can help with these issues.

Relying on exercise only:

Exercise is great and we all should do it but relying on exercise alone to lose weight isn’t going to work. Unless you change your dietary intake, you are unlikely to see any reduction in weight. In theory you can enjoy all foods in moderation if you are mindful about portion size.

Motivation to lose weight:

Be prepared, plan well balanced nutritious meals in advance.

Stay hydrated, drink plenty of water.

Aim to achieve quality sleep.

Get sound professional advice on medical weight loss options available.

Treatment options:

Psychological support:

If you feel that emotional/comfort eating is an issue to you, ensure you factor in expert professional support to deal with emotional eating as well as physical hunger. This can involve many aspects of treatment such as habit change, removing triggers, finding non-food alternatives to dealing with negative emotions, dealing with past traumas, anxiety, stress and depression. The Gateway Health programme, unlike other bariatric providers, deals with the psychological aspects following weight loss surgery aftercare.

Diet pills:

Why rely on pills? Many pills flush out vital vitamins and minerals which are essential for losing weight and avoiding disease.

We understand the desperation to lose weight in the short term, but we are concerned with your long-term health.

Drugs do not give a long-term solution and can be very costly… for example the average cost of a MONTHLY private prescription for the weight loss drug Saxenda is approximately £600-800! When you consider the costs of paying for these drugs over many, many months AND their side effects, would it not be more cost effective to look for a permanent solution?

If you can lose weight eating smaller portions and exercising more then we sincerely congratulate you.

However, we understand this is easier said than done.

There are many other factors in the mix….  genetics, metabolic, biological, behavioural and psychological barriers to losing weight …

Gateway Health offer only time served, evidence-based weight loss surgeries.

Our gold standard after care programme addresses dietary, exercise, behavioural and psychological issues, which result in superior weight loss results and weight maintenance.

Call Gateway Health 0345 9000 339

Bariatric surgery is without doubt the most effective weight loss method available.

Choose a Bariatric provider who not only has UK leading safety statistics (check out he NBSR – national Bariatric Register) but also provides an all-encompassing after care programme.

Gateway Health are the market leaders in Bariatric Surgery with the most comprehensive support and after care programme with industry leading results.

The truth about weight loss surgery.

As your body weight increases, your life expectancy decreases.

People who are severely obese often have a number of weight related medical conditions that greatly increase the risk of dying early. For example, type 2 diabetes, high blood pressure, high cholesterol, heart disease and stroke, gall bladder disease, some cancers and sleep apnoea.

The risks of bariatric surgery are less than most other operations, including gallbladder and hip replacement surgery.

Many bariatric patients have poor health prior to surgery but the surgical risks are still exceptionally low.

Gateway Health’s lead Bariatric Surgeon Mr Roger Ackroyd has an exceptional safety record.

All UK Bariatric surgeon’s outcomes can be found on the national Bariatric Register. (>nbsr)

There are many studies that show improvement or resolution of life-threatening obesity-related diseases following bariatric surgery.

The benefits of bariatric surgery far outweigh the risks.

The team at Gateway Health are highly qualified bariatric experts who are committed to providing compassionate and individualised care.

We offer only time served evidence- based weight loss surgeries.

Our expert aftercare programme addresses dietary, exercise, behavioural and psychological support, resulting in superior weight loss results and long-term weight maintenance.


The truth about portion sizes following bariatric surgery.


Bariatric surgery creates a portion control system. There are slight variances with the different surgery options, but generally:

  1. In the early days following weight loss surgery you will only be eating a few spoonfuls of pureed food several times a day.
  2. After 3-4 weeks you will progress onto small portions of soft, mushy foods
  3. After 3-6 months you will have typically progressed onto a normal texture diet, your portion size is typically a side plate portion of food.

There is no reason why you cannot follow a normal healthy eating pattern, eat out with friends and have a normal healthy social life.

The Gateway Health team prepare you fully before surgery so that you are organised and have appropriate foods ready at home for after your discharge from hospital.

We give you step by step written advice also and follow up daily after your discharge from hospital, to reassure and guide you through the dietary stages and to be on hand for any questions or advice you may need.

Our aftercare also includes behavioural and emotional change support.

Everybody is motivated to lose weight for different reasons, what’s yours?

We all know that losing weight decreases your risks of dying early from weight related illnesses such as type 2 diabetes, heart disease, stroke, some cancers, high blood pressure, high cholesterol etc.

But there are many other benefits to losing weight …….

Improved sleep

Less joint pain

Increased energy

Increased confidence

Improved mood

Better complexion

People usually treat you better

Your children will eat better

You often are more open to trying new experiences and activities

Breathe easier

Clothes look and fit better

Sex drive improves

Your memory may improve

Food tastes better

You save money as not spending as much on food


Whatever your reason to lose weight, whether it is to improve health, confidence, mood, energy levels or to live longer…….. you get all the benefits if you make a success of it.

Preventing common problems after surgery.

Tips to prevent common problems:

Eat slowly, chew foods thoroughly and stop eating as soon as you feel satisfied to avoid discomfort, nausea and vomiting and ultimately stretching your stomach pouch.

To prevent nutritional deficiencies always take your vitamin and mineral supplements as directed by your bariatric team alongside a healthy balanced diet. Symptoms of deficiencies can be: fatigue, achy muscles, tingling feet, calves or hands.

Some hair loss can be experienced around months 4-8 post surgery, this is caused by rapid weight loss and/or lack of protein or vitamins/minerals in the diet. To prevent this, patients should consume the amount of protein recommended by their bariatric dietitian (usually 60mg daily) and take vitamins/minerals as directed. Gateway Health patients are usually recommended to take 2 x complete multi vitamin and mineral supplements per day or 1 x prescribed Forceval vitamin and mineral supplement a day. Be reassured that we do find that hair does grow back after 12 months and often thicker than it was before surgery.

Dehydration is caused by drinking too little fluid or by persistent vomiting. Signs and symptoms include dark and strong-smelling urine, dry mouth, headache, and fatigue.  Drinking with meals is to be avoided after bariatric surgery, so it is important to sip liquids frequently throughout the day to avoid dehydration.

Dumping syndrome is caused by food emptying too quickly from the new stomach after gastric bypass surgery. Signs and symptoms include diarrhoea, nausea, cold sweats, and light-headedness. Avoid eating or drinking refined sugars and high-fat foods or drinks and wait for 30 minutes after finishing your meals before drinking.

After weight loss surgery you eat less food and fibre. To prevent constipation drink plenty of water, exercise daily, include fibre in your diet and we find taking a fibre supplement such as Benefiber or Fibresure is helpful. (found in large supermarkets near the vitamin aisle)

If you find it difficult to follow advice, whether that is due to poor motivation, poor understanding of nutrition/what is required, poor planning, lack of knowledge as to how to prepare meals/meet your dietary needs or emotional eating …. It is important to seek professional expert advice to avoid a poor result and future weight regain.

Weight loss surgery is just a tool, if long term dietary, exercise and mind set are not changed, weight regain is a real possibility. Find a bariatric provider who can expertly meet all of your individual needs.