Ask Your Bariatric Dietitian: Common Nutrient Deficiencies

Article By: Maria Tucker, MPH, RDN, LDN, CDCES

Maria Tucker is a Registered Dietitian and Certified Diabetes Educator with over 20 years of experience assisting patients with diabetes, obesity, and nutrition-related conditions.

Nutrient deficiencies and malnutrition may not be thought of as being present with obesity. When someone hears the word malnutrition, one often thinks of a person who is underweight and suspected of not getting adequate food to eat. However, someone can also be suffering from malnutrition even with obesity. Consuming more calories from nutrient-poor foods, fewer healthier types of food, or more calories than recommended can lead to nutritional deficiencies that can go undiagnosed and lead to health problems with long-term consequences.

1) Nutrient deficiencies after bariatric surgery.

When preparing for bariatric surgery, it is important to check for the presence of nutrient deficiencies since bariatric surgery puts patients at risk for certain long-term vitamin and mineral deficiencies. Bariatric surgery centers include pre and postoperative screening guidelines and supplementation for nutrient deficiencies which are recommended by several organizations including The American Society for Metabolic and Bariatric Surgery (ASMBS), American Association of Clinical Endocrinologists (AACE), The Obesity Society (TOS), Obesity Medicine Association (OMA), and American Society of Anesthesiologists (ASA). In 2019, they co-sponsored the development of updates to the clinical practice guidelines.

According to results of a recent study published by the Academy of Nutrition and Dietetics in 2020, a high prevalence of nutritional deficiencies including vitamin B12, vitamin D, folate, and iron is present in bariatric surgery patients (but mainly in vitamin D and iron).

The 2019 Bariatric Surgery Guidelines update includes recommendations for postoperative screening for deficiencies in vitamins B12, folate, vitamin D, vitamin A, calcium, zinc, copper, and iron, particularly for patients who have undergone Roux-en-Y gastric bypass or biliopancreatic diversion/duodenal switch. Screening for thiamin (vitamin B1) is recommended for high-risk groups or those with risk factors for thiamin deficiency.

2) Common deficiency symptoms & food sources.

To help you maintain or improve your vitamin and mineral blood levels before and/or after bariatric surgery, here is a list of the most common nutrient deficiencies, examples of deficiency symptoms, and some food sources of these nutrients you can add to your diet.

 Nutrient Common Deficiency Symptoms Food Sources
Vitamin A

Night blindness or difficulty seeing in low light

Beef liver, sweet potato, spinach, pumpkin, carrots

Vitamin B12

Anemia, fatigue, dementia, palpitations, numbness, and tingling of hands and/or feet

Fish, meat, poultry, eggs, dairy

Vitamin D

Osteomalacia, osteoporosis, rickets, diarrhea

Salmon, trout, mushrooms, vitamin D fortified dairy or plant-based milk


Megaloblastic anemia, ulcerations on the tongue and mouth, GI symptoms, changes in hair, skin, or fingernail pigmentation

Beef liver, spinach, black-eyed peas, fortified breakfast cereal and white rice, asparagus


Osteoporosis, rickets, osteomalacia, brittle nails, cramps, tooth decay, irritability

Yogurt, fortified orange juice, part-skim mozzarella, sardines


Anemia, diarrhea, hypercholesterolemia, hair loss, fatigue, ataxia (impaired balance)

Beef liver, oysters, potatoes, shiitake mushrooms, cashews


Anemia, GI disturbances, weakness, fatigue, impaired cognitive and immune function, impaired exercise or work performance and body temperature regulation, brittle nails

Fortified breakfast cereal, oysters, white beans, beef liver, lentils, spinach, firm tofu


Anorexia, confusion, short-term memory loss, irritability, numbness of hands and feet

Fortified breakfast cereal, trout, pork chop, black beans, mussels

Source: NIH Office of Dietary Supplements Fact Sheet

3) The role of bariatric vitamins.

Vitamins and minerals are essential substances we need for our bodies to function normally. In order for people to meet requirements for vitamins and minerals, the Dietary Guidelines for Americans 2020-2025 recommends following a healthy eating pattern and consuming nutrient-dense foods. For pre and post-bariatric surgery patients, however, the requirements for some nutrients can be higher due to the increased risk of deficiencies after surgery. To meet these higher nutrient requirements and prevent long-term nutritional deficiencies, it is important to take vitamins and minerals in the recommended doses. Taking recommended bariatric surgery specific multivitamins with minerals, as well as single nutrient supplements is a must. There are several options for bariatric surgery specific vitamins and minerals. Immediately post-surgery, chewable, dissolvable, crushable, or liquid bariatric surgery multivitamins with minerals and other nutrients are recommended to prevent GI discomfort and increase adherence.

BariMelts offers fast-dissolving, great-tasting options that meet recommended nutrient requirements. The general recommendation for patients is to take chewable, dissolvable, crushable, or liquid multivitamin options for three months post-surgery, then transition to other forms.

In addition to fast-dissolving vitamin options, BariMelts also offers a caplet form patients can switch to called The Step Up. These caplets have a more uniform dispersion of nutrients to avoid dose-dumping and support gentle absorption releasing the nutrients gradually. Patients report decreases in GI discomfort and nausea when taking The Step Up, which increases their adherence to taking their recommended supplements.

If you are preparing for or have had bariatric surgery, it is crucial for you to take recommended vitamins and minerals to maintain good nutrition and prevent deficiencies long-term. There are several options to choose from for your nutritional supplement needs, and a Registered Dietitian Nutritionist specializing in bariatric surgery nutrition can assist you in finding the best option that meets your particular needs.

BariMelts provides general recommendations, not to be construed as medical advice. Please consult your doctor.

Leave a comment

Please note, comments must be approved before they are published

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.