Q: I have a patient who recently underwent bariatric surgery. Her surgeon warned against the potential for vitamin B1 and C deficiencies as well as corneal changes, but didn’t elaborate. Any information would be appreciated.

A: Patients who undergo a gastric bypass procedure need to have post-op counseling, adapt their lifestyle and take a multivitamin, says Jeffrey Anshel, O.D., president of the Ocular Nutrition Society. “It depends on which surgery the patient is having done, plus the amount of stomach and small intestine being bypassed—different sections absorb different nutrients.”

How Do You Discuss Weight With a Patient? Weight is still a touchy subject for many patients. But, says Dr. Anshel, it is your responsibility to bring up related ophthalmic concerns. “One technique we discuss in the ONS is beginning with the many studies that link obesity with chronic eye disease. These studies show that body-mass index is a risk factor. Make it a legitimate, physician-originated discussion, and it skirts the problem,” he says. “And, if it’s approached in that way, we not only look to resolve eye disease but to prevent it.” Another helpful tactic:  Provide information about nutrition and its effects on the eyes in your waiting room. “You need to open the eyes of the patient to the fact that nutrients and weight affect the health of the eyes,” says Dr. Anshel.

Penelope Edwards, M.P.H., C.N.S., owner of Nutrition Counts Counseling, points out that it is unlikely a patient will be deficient in just one vitamin. “According to the most recent reviews, bariatric surgery patients are commonly at risk for deficiencies of water-soluble vitamins B₁₂, B₁, folate, C, fat soluble vitamins A, D, E and K, as well as the minerals iron, zinc, selenium, calcium, magnesium and copper,” she says.1 “Deficiencies of vitamin B₁₂ and iron are perhaps the most commonly observed, but keep in mind that these patients are more likely to have marginal levels or deficits of multiple nutrients rather than a deficiency of a single nutrient.”

Restrictive procedures, such as gastric banding, are less likely to cause nutritional deficits; none of the intestine, which absorbs most of the iron and calcium of the diet, is bypassed.^1,2 But, malabsorptive procedures, such as biliopancreatic diversion, or mixed restrictive/malabsorptive procedures (e.g., Roux-en-Y gastric bypass) can cause nutritional deficiency—especially when patients do not take the required supplements after surgery.¹

“The risk for micronutrient depletion is highest after surgeries that affect digestion and absorption, such as the Roux-en Y gastric bypass, the most common type of weight loss surgery,” says Ms. Edwards. “Roux-en Y gastric bypass greatly increases the risk for vitamin B₁₂ deficiency. But other B vitamins—especially B₁ and folate—as well as calcium and iron can also be affected.”

Restrictive procedures still pose a risk to patients’ nutritional intake, though. “In the past, it was thought that specific nutrient deficiencies wouldn’t be a problem in patients undergoing ’restrictive’ types of surgery,” says Ms. Edwards. “However, poor food choices, food intolerances, and the limited size of food portions all contribute to the risk of vitamin and mineral shortfalls.”  

Your patient will have heard this before the bypass procedure as well, but ensure that she is taking a full-spectrum multivitamin. “Most bariatric surgery centers offer dietary guidelines for how to eat and drink to avoid complications post-op, as well as how to consume nutrient-dense foods for the long haul,” says Ms. Edwards. “But, the problem is that many gastric bypass patients don’t follow up with their surgeons as advised. It’s estimated that the number of obesity surgery patients in the U.S. will exceed one million in the next few years, so nutritional vigilance by all health care professionals will be increasingly important.

Adds Dr. Anshel: “Other important vitamins are B₁₂, as well as vitamin D and calcium. The patient is absorbing less of these. But generally, the patient can expect to be on a lifelong regimen of full-spectrum multivitamins."

If a patient experiences complications, noncompliance with this lifelong regimen may well be the cause. “The supplemental level required to prevent deficiencies for many nutrients far exceeds what any healthy diet can supply,” says Ms. Edwards. “Patients should also be reminded to visit their physician regularly, because even those already taking supplements should be closely monitored for vitamin deficiencies.”

Also, Dr. Anshel recommends that patients use either a liquid or a capsule multivitamin for better absorption rates.

Ocular signs of hypovitaminosis A include night blindness and dry eye, says Dr. Anshel.³ In extreme cases of hypovitaminosis A, xerosis and corneal scarring are also possible.^3,4

“Drying of the conjunctiva with Bitot’s spots, dry skin and poor wound healing can also be early symptoms of deficiency,” says Ms. Edwards. “Advanced deficiency symptoms also include corneal damage, keratomalacia, endophthalmitis, and hyperkeratinization of the skin.”

Optic neuritis and oculomotor problems indicate hypovitaminosis B—and keep in mind that age may play a role in how well the patient absorbs vitamin D, Dr. Anshel adds.

“One early sign of low vitamin B₁ levels is fatigue, as this vitamin is required for the energy-yielding metabolism of carbohydrates,” Ms. Edwards says. “Overt deficiency can lead to dry beri-beri or even Wernicke’s encephalopathy, which affect the nervous system. A patient with dry beri-beri may manifest weakness, dizziness, blurred vision, peripheral neuropathies (often beginning with a tingling in the toes and hands), and difficulty walking. You’re likely to see mental confusion and nystagmus, too, when Wernicke’s is involved. Many of these symptoms can be mistaken for stroke, so it’s important to know a patient’s surgical history.”

If you diagnose hypovitaminosis, restoring the vitamin intake should clear up the condition, Dr. Anshel says. Make sure that patients are aware of the diagnosis and management, and follow up with them as best as you can to ensure that they are staying with their multivitamin regimen. This treatment regimen should be comanaged with the patient’s primary care physician, as higher levels of vitamin intake may be temporarily necessary.

1. Malone M. Recommended nutritional supplements for bariatric surgery patients. Ann Pharmacother. 2008 Dec;42(12):1851-8.
2. Weight-Control Information Network, National Institute of Diabetes and Digestive and Kidney Diseases. Bariatric Surgery for Severe Obesity. Available at: www.win.niddk.nih.gov/publications/gastric.htm (Accessed July 2010).
3. López-Rodríguez N, Faus F, Sierra J, et al. Night blindness and xerophthalmia after surgery for morbid obesity. Arch Soc Esp Oftalmol. 2008 Feb;83(2):133-5.
4. Lee BW, Hamilton SM, Harris SP, Schwab IR. Ocular complications of hypovitaminosis A after bariatric surgery. Ophthalmology 2005 Jun;112(6):1031-4.