A woman who had weight-loss surgery eight years earlier suddenly lost her vision due to severe vitamin A deficiency. Doctors discovered she wasn’t taking the required vitamins after her surgery. This case study shows that people who have certain types of weight-loss surgery need to keep taking vitamin supplements for life, even years after the procedure. When she received high-dose vitamin A treatment, her vision improved significantly. The research reminds doctors and patients that skipping vitamin supplements after weight-loss surgery can lead to serious, sight-threatening complications that might not show up until many years later.

The Quick Take

  • What they studied: A single patient who developed severe vitamin A deficiency and eye damage years after having weight-loss surgery, and what doctors learned from treating her
  • Who participated: One woman in her early 40s who had undergone biliopancreatic diversion with duodenal switch surgery (a type of weight-loss surgery) eight years before experiencing vision problems
  • Key finding: The patient had stopped taking required vitamin supplements after her surgery and developed severe vitamin A deficiency that caused permanent eye damage (keratomalacia). High-dose vitamin A treatment given through injections helped restore much of her lost vision within two months
  • What it means for you: If you’ve had certain types of weight-loss surgery, taking vitamin supplements isn’t optional—it’s essential for life. Skipping supplements can cause serious health problems, including blindness, even years after surgery. Talk to your doctor about which vitamins you need and commit to taking them consistently

The Research Details

This is a case report, which means doctors documented the medical history and treatment of one patient with an unusual condition. The patient came to the hospital with sudden vision loss and was examined by eye specialists who found specific signs of vitamin A deficiency in her eyes. Blood tests confirmed she was severely deficient in vitamins A, D, E, and K1. The doctors reviewed her medical records and discovered she hadn’t been following up with her bariatric surgery clinic or taking her prescribed vitamin supplements for years. They then treated her with high-dose vitamin A injections and special nutrition support given through an IV, and tracked how her vision improved over time.

Case reports are important because they document rare or unusual complications that doctors might otherwise miss. This case is valuable because it shows that serious vitamin deficiencies can develop silently years after weight-loss surgery, and that patients might not realize they have a problem until it becomes severe. By sharing this case, doctors can learn to recognize these warning signs earlier and remind patients how critical vitamin supplements are after surgery.

This is a single case report, which means it describes one patient’s experience rather than testing many people. While case reports can’t prove something happens to everyone, they’re valuable for raising awareness about rare complications. The strength of this report is that it includes detailed medical records, lab results, and eye examination findings. The main limitation is that we can’t know how common this problem is or whether the same treatment would work for everyone, since only one patient was studied.

What the Results Show

The patient presented with sudden vision loss that had developed over time. Eye doctors found specific signs of advanced vitamin A deficiency, including Bitot’s spots (white patches on the eye) and keratomalacia (softening and scarring of the cornea, the clear front part of the eye). Blood tests showed she was severely deficient not just in vitamin A, but also in vitamins D, E, and K1. The patient admitted she had stopped attending follow-up appointments at her bariatric surgery clinic and had not been taking her prescribed vitamin supplements. When treated with high-dose vitamin A injections and IV nutrition support, her vision improved significantly within two months, and the eye damage began to heal.

The patient also had deficiencies in multiple other fat-soluble vitamins (D, E, and K1), which can happen together because they’re all absorbed the same way in the intestines. This suggests that patients who skip vitamin supplements after weight-loss surgery are at risk for multiple serious deficiencies at once. The case also showed that even though the patient had surgery eight years earlier, the vitamin deficiency developed and caused severe damage, proving that the need for supplements doesn’t decrease with time.

Vitamin A deficiency is known to be a rare but serious complication of certain weight-loss surgeries in developed countries. Most cases reported in medical literature happen within the first few years after surgery, so this case is unusual because the severe deficiency developed eight years later. This suggests that doctors and patients may underestimate how long vitamin supplementation needs to continue. Previous research has shown that poor follow-up care and skipping supplements are major risk factors, which this case confirms.

This is a single case study, so we cannot know how often this complication occurs or whether it would happen to most people who skip supplements. We don’t know if the same treatment would work equally well for other patients. The case doesn’t tell us how many people who have this surgery actually stop taking supplements or how many develop deficiencies without realizing it. Additionally, this patient may have had other factors that made her more vulnerable to deficiency that weren’t fully explored.

The Bottom Line

If you have had biliopancreatic diversion with duodenal switch surgery (or similar malabsorptive weight-loss surgery), you must take vitamin supplements for life—this is not optional. Work with your bariatric surgery team to establish a supplement routine and attend regular follow-up appointments. Have your vitamin levels checked regularly through blood tests. If you experience vision changes, eye pain, or any unusual symptoms, see a doctor immediately. High confidence: vitamin supplementation prevents these serious complications.

This is most relevant to people who have had malabsorptive weight-loss surgeries (particularly biliopancreatic diversion with duodenal switch). It’s also important for their family members, caregivers, and healthcare providers to understand the risks. People considering this type of surgery should understand the lifelong commitment to vitamin supplements before proceeding. People who have had other types of weight-loss surgery should also be aware, as similar (though usually less severe) vitamin deficiencies can occur.

Vitamin A deficiency can develop silently over months or years without obvious symptoms. Serious eye damage, as in this case, may not appear until the deficiency is very advanced. Once treatment begins with high-dose vitamins, improvement can be seen within weeks to months, but some eye damage may be permanent if caught too late. This is why prevention through consistent supplementation is far better than treatment after damage occurs.

Want to Apply This Research?

  • Set up a daily reminder to log your vitamin supplement intake (vitamin A, D, E, K1, and any others prescribed). Track the specific dose and time taken each day. Include a monthly note about any vision changes, eye discomfort, or other symptoms.
  • Use the app to create a non-negotiable daily vitamin routine: set phone reminders at the same time each day, track which supplements you’ve taken, and mark off each day you complete your full supplement regimen. Share your supplement schedule with a family member or friend who can help hold you accountable.
  • Schedule quarterly check-ins with your bariatric surgery team through the app. Before each appointment, review your supplement compliance rate from the app. Track any new symptoms (especially vision changes, dry eyes, or night blindness) and report them immediately. Keep records of your lab test results in the app to monitor vitamin levels over time.

This case report describes one patient’s experience and should not be considered medical advice. If you have had weight-loss surgery, consult with your bariatric surgery team about your specific vitamin supplementation needs and follow-up schedule. If you experience vision changes, eye pain, or other concerning symptoms, seek immediate medical attention. Do not start, stop, or change any vitamin supplements without consulting your healthcare provider. This information is for educational purposes and does not replace professional medical diagnosis or treatment.