Vitamin A Deficiency Related to Metabolic & Bariatric Surgery

Vitamin A Deficiency Related to Metabolic & Bariatric Surgery - Bariatric Fusion

If you have undergone metabolic and bariatric surgery (MBS), your healthcare team probably let you know about the high risk of vitamin and mineral deficiencies post-op.

The intestinal re-routing performed during procedures, like gastric bypass surgery (RYGB) or duodenal switch, cause malabsorption of essential nutrients and restriction of food intake, resulting in the need for lifelong vitamin and mineral supplementation. However, the risk of micronutrient deficits varies based on the type of surgery performed and can easily be prevented.*

How serious are these micronutrient deficiencies, and are there specific areas of concern? In this blog, we discuss the importance of vitamin A and recommended supplementation after MBS.*

The Role of Vitamin A

Vitamin A is a fat-soluble vitamin that supports immune function, healthy vision, reproduction, wound healing, bone growth, and tooth development. It also helps to maintain healthy function and maintenance of your organs.*

Forms of Vitamin A

forms of vitamin a

Different forms of vitamin A can be found in food sources and supplements.

Retinol and retinoic acid are found primarily in dairy products, fish, and liver. Beta carotene, found in orange and dark green fruits and vegetables, is another form of vitamin A that is considered an antioxidant. You can also find these forms of vitamin A in supplements.

The many variations of vitamin A found on supplement labels can get very confusing. There are retinol, retinol esters, retinoic acids, and so on. Retinol and retinyl esters are the most abundant forms found in the body, including retinyl palmitate.

The American Society for Metabolic and Bariatric Surgery (ASMBS) recommends retinol derivatives of vitamin A as opposed to beta carotene because retinol derivatives (including retinyl palmitate) are better absorbed. It takes about twice the amount of beta carotene to meet the body’s vitamin A requirements when compared to retinol because beta carotene is considered the weakest form of vitamin A. (1)*

Dry Vitamin A

Vitamins fall into two categories: water-soluble and fat-soluble. They are categorized by their solubility and how they are stored in the body.


Most vitamins are water-soluble. This means they dissolve in water and require regular replacement from your diet because the body only absorbs what it needs and excretes the rest. This would include all eight B vitamins (thiamine, riboflavin, niacin, pantothenic acid, vitamin B6, biotin, folate, vitamin B12) and vitamin C.

Fat-Soluble Vitamins

There are only four fat-soluble vitamins: A, D, E, and K. They require fat to dissolve, so you will most commonly find them in high-fat foods.

The body stores these vitamins in the liver and fatty tissue for later use; it's more common to reach toxic levels because they are eliminated slowly over time.

As a fat-soluble vitamin, vitamin A can be manufactured into a water-soluble form for those with severe absorption issues. This type of vitamin A is called dry, water-miscible, or water-soluble vitamin A.

Is dry vitamin A required after metabolic and bariatric surgery? Not necessarily. Individual needs vary, even between those who have undergone the same surgery.

Before purchasing a vitamin supplement, follow up with a qualified healthcare professional to best assist you in deciding whether a dietary supplement is suitable based on your individual needs.

Vitamin A Deficiency

Research has proven a higher incidence of certain nutrient deficiencies, including vitamin A, among individuals with obesity considered for metabolic and bariatric surgery. (2)*

Why is this the case? Various forms of vitamin A are absorbed in part of the small intestine called the duodenum and a large portion of the small intestine is bypassed during duodenal switch (DS) surgery, resulting in a high risk of vitamin A deficiency. Malabsorptive procedures also result in inadequate absorption of dietary fat, which vitamin A requires to be adequately absorbed.

Vitamin A supplementation is recommended after all bariatric procedures. The American Society for Metabolic and Bariatric Surgery (ASMBS) nutritional guidelines state that within four years post-op, vitamin A deficiency occurs in up to 70% of patients with roux-en-y gastric bypass surgery and duodenal switch. (3)*

Bariatric ADEK multivitamins contain higher levels of these fat-soluble vitamins to compensate for the poor absorption of nutrients and food restriction following malabsorptive bariatric procedures.*

Signs and Symptoms of Vitamin A Deficiency

Routine lab work is recommended post-op to monitor micronutrient levels. Some common symptoms of vitamin A deficiency include:

  • Acne
  • Dry hair
  • Insomnia
  • Fatigue
  • Growth impairment
  • Hyperkeratosis (thickening skin)
  • Night blindness
  • Immune impairment

Any of the symptoms above should be reported immediately to your healthcare provider.

Vitamin A Supplementation for Prevention*

The ASMBS guidelines recommend a daily multivitamin containing specific dosages of vitamin A based on each procedure.* To put into perspective, the Recommended Dietary Allowance (RDA) for the average individual is 700 - 900 mcg of vitamin A daily.

Below are the ASMBS vitamin A recommendations for metabolic and bariatric patients that should be found in a bariatric multivitamin to support daily nutrition after surgery.*

Recommendations may vary based on your individual needs, and supplementation will also have to be adjusted if you are pregnant or planning to become pregnant post-surgery. You must follow up with your bariatric team regarding the supplements you are taking, as high levels of vitamin A (retinol) found in most bariatric supplements can pose a health concern for pregnant women.

Learn more about pregnancy after gastric bypass.*

Vitamin A Supplementation for Deficiency*

A bariatric multivitamin is often recommended post-surgery. But what happens when you are deficient in one or more micronutrients? Additional supplements can be used in addition to a bariatric multivitamin to support healthy micronutrient levels.*

Single micronutrient supplements (i.e., standalone vitamin A) should contain the nutrient's most bioavailable or absorbable form. They can also be offered as a combination of micronutrients that work together to support absorption and achieve healthy blood levels in the body.*

For example, you may see iron-containing vitamin C, which supports iron absorption. Zinc and copper should be supplemented together, as they are needed in balanced amounts.*

vitamin a supplementation for deficiency*


Bariatric-specific multivitamins typically follow the ASMBS guidelines and support the specific needs of post-surgical patients. In contrast, the average over-the-counter multivitamin supplements do not contain adequate micronutrients to meet bariatric needs.*

Experienced bariatric healthcare practitioners designed these guidelines to ensure patients receive the vitamins and minerals required to support nutrition and weight management support. Additional supplements may be required throughout your health journey, so it’s important to keep your healthcare practitioner informed.*

Bariatric Fusion provides various options for a daily multivitamin regimen necessary for all metabolic and bariatric surgery patients.*

See also: Gastric Bypass and Kidney Stones


  1. The American Journal of Clinical Nutrition. 2012; 96(5): 1193S-1203S
  2. Obes Facts. 2022; 15(1): 19-25
  3. Surgery for Obesity and Related Diseases. 2020: 175-247

*These statements have not been evaluated by the Food & Drug Administration (FDA). These products are not intended to diagnose, treat, cure or prevent any disease.

This blog is for information and education purposes only. This information is not intended to substitute professional medical advice, diagnosis, or treatment. Please consult with your physician or another qualified health provider with any questions in regards to a medical condition. A qualified healthcare professional can best assist you in deciding whether a dietary supplement is suitable based on your individual needs.

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