After bariatric surgery, we need vitamins that meet the specific needs of our new GI tract. That is why bariatric-specific vitamins are recommended instead of over-the-counter vitamins. Did you know that not all vitamins are absorbed the same way? There are two types: water-soluble and fat-soluble. Here we look at fat-soluble vitamins, why deficiencies occur after bariatric surgery and what you can do to prevent them.
Key takeaways
- The fat-soluble vitamins are A, D, E and K; they are absorbed in the duodenum, which is bypassed in the RNYGB and BPD/DS.
- Vitamin D is at the highest risk: deficiency affects up to 90% of patients before and up to 100% after surgery.
- Dry, water-miscible forms do not need to be taken with fat.
- Follow the ASMBS guidelines and get your lab values checked as recommended.
What are fat-soluble vitamins? Where are they absorbed?
Fat-soluble vitamins are vitamins A, D, E and K. They are absorbed along with dietary fat and stored in the body's fat tissue – unlike water-soluble vitamins, which are absorbed in water, with any excess excreted in urine. Fat-soluble vitamins are absorbed in the duodenum, the first part of the small intestine. The duodenum is also the part of the small intestine that is bypassed in the Roux-en-Y gastric bypass (RNYGB) and the biliopancreatic diversion with duodenal switch (BPD/DS).1
What contributes to fat-soluble vitamin malabsorption after surgery?
Several factors affect the absorption of fat-soluble vitamins after all bariatric surgeries:1
- Patients eat less food after surgery.
- There are fewer gastric juices to aid absorption.
- Dietary fat is commonly not well tolerated after surgery. Post-surgery diets are typically high protein, low sugar and low fat (not to be confused with no fat).
- Bypassing the duodenum (particularly in the RNYGB and BPD/DS) is arguably the most important influence on nutrient malabsorption after bariatric surgery.
A low fat intake combined with fat malabsorption results in the fat-soluble vitamins being malabsorbed too.
Which fat-soluble vitamins are at highest risk?
| Vitamin | Deficiency | Signs and symptoms |
|---|---|---|
| Vitamin D (highest risk) | Up to 90% of patients with obesity before surgery2; prevalence of up to 100% after surgery3 | Low blood calcium levels, muscle spasms, tingling, cramping and metabolic bone disease2 |
| Vitamin A | 14% of patients with obesity before surgery2; up to 70% after RNYGB or BPD/DS3 | Night blindness, Bitot's spots, poor wound healing and loss of taste. Severe deficiency can lead to corneal damage, blindness and abnormally dry skin2 |
| Vitamin E | Only 2.2% before surgery2; rare after surgery, though it does occur3 | Hyporeflexia, gait disturbances, neurological damage, muscle weakness and haemolytic anaemia2 |
| Vitamin K | No data before surgery2; rare after surgery, though it does occur3 | Haemorrhage, bruising, bleeding gums, delayed blood clotting and nosebleeds2 |
What can you do to prevent fat-soluble vitamin deficiencies?
1. Take the recommended amount of fat-soluble vitamins for your surgery daily
Follow the ASMBS guidelines for fat-soluble vitamins to prevent deficiencies:3
| Surgery | Vitamin A | Vitamin D* | Vitamin E | Vitamin K |
|---|---|---|---|---|
| Sleeve gastrectomy | 5,000–10,000 IU/d | 3,000 IU/d | 15 mg/d | 90–120 μg/d |
| RNYGB | 5,000–10,000 IU/d | 3,000 IU/d | 15 mg/d | 90–120 μg/d |
| BPD/DS | 10,000 IU/d | 3,000 IU/d | 15 mg/d | 300 μg/d |
* Doses are for supplemental vitamin D3.
2. Look for dry, water-miscible fat-soluble vitamins in your bariatric multivitamin
For example, Celebrate's Bariatric Multivitamin ADEK capsules or chewable tablets. Dry, water-miscible forms of fat-soluble vitamins in your multivitamin will enhance absorption because they do not need to be taken with fat.
3. Get your nutritional lab values checked as recommended
The ASMBS guidelines recommend routine screening for vitamin D after all surgeries, vitamin A particularly after RNYGB and BPD/DS, and vitamins E and K for patients showing symptoms.3
4. Stay connected with your bariatric team
As always, speak with your bariatric team about nutritional supplementation and what is appropriate for you.
Sources
- Sawaya RA, et al. Vitamin, mineral, and drug absorption following bariatric surgery. Current Drug Metabolism. 2012;13(9):1345-55. doi:10.2174/138920012803341339
- Parrott J, et al. American Society for Metabolic and Bariatric Surgery Integrated Health Nutritional Guidelines for the Surgical Weight Loss Patient 2016 Update: Micronutrients. Surgery for Obesity and Related Diseases. 2017;13(5):727–741. doi:10.1016/j.soard.2016.12.018
- Mechanick JI, et al. Clinical Practice Guidelines for the Perioperative Nutrition, Metabolic, and Nonsurgical Support of Patients Undergoing Bariatric Procedures – 2019 Update. Obesity. 2020;28(4). doi:10.1002/oby.22719
This article is for general information only and does not replace personal medical advice. Always discuss your situation, blood test results and supplementation with your bariatric team or healthcare provider.