B6, Multivitamins and the Bariatric Patient: What You Need to Know

B6, Multivitamins and the Bariatric Patient: What You Need to Know

Featuring Dr Terri-Lynne South on The Bari Chronicles Podcast, Season 4 Episode 1
Published: 20 October 2025

Supplements After Surgery – Where Do We Start?

After bariatric surgery, most patients are told they’ll need a multivitamin.
But what kind of supplement? How often? And how much is too much?

In the latest episode of The Bari Chronicles, host Damo Verner sat down with Dr Terri-Lynne South, a GP and dietitian with over 25 years’ experience, to unpack the complex world of post-surgery vitamins—especially the controversial rise in vitamin B6 toxicity.

“I agree that everyone who’s had bariatric surgery needs supplementation,” says Dr South. “But the type of supplement and how much you need depends on your individual surgery and your own body.”

Regular blood testing is vital—typically at 3, 6, and 12 months after surgery, and then at least once or twice a year for life.
These tests ensure your supplements are doing what they should—without tipping your vitamin levels too high.

The B6 Backlash – When ‘Healthy’ Goes Too Far

Vitamin B6, long thought to be harmless because it’s water-soluble, has recently been making headlines.
Turns out, you can have too much of a good thing.

“The assumption used to be that if you had too much B6, you’d just pee it out,” explains Dr South. “But we now know excessive B6 can cause peripheral neuropathy—nerve pain, numbness, and weakness.”

Alarmingly, many Australians may be unknowingly overdosing. B6 isn’t only in multivitamins—it hides in energy drinks, protein powders, sleep aids, and magnesium tablets.
Even small daily doses can accumulate when taken from multiple sources.

Why It’s a Bigger Problem Than You Think

There’s a gap in regulation.
Food products like Red Bull are overseen by Food Standards Australia New Zealand (FSANZ), which caps B6 content at 10 mg per serve.
But supplements fall under the TGA, where tablets can legally contain up to 50 mg — and some “complex” products go even higher.

“You might buy a magnesium supplement or sleep aid not realising it contains B6,” Dr South warns. “And it’s not always labelled clearly—it might appear under names like pyridoxine or pyridoxal.”

A 2023 independent review found that if limits were reduced, more than 100 Australian products would need to move behind the pharmacy counter—a shift that would protect consumers but face huge industry pushback.

What About Bariatric Patients?

Surprisingly, it’s not just a bariatric issue.

“The bariatric community noticed it first because they’re tested more often,” says Dr South. “But anyone taking multiple supplements, energy drinks or sleep aids could be at risk.”

Still, bariatric patients are more likely to take several products daily, making careful management and team-based review essential.
Regular checks with your dietitian and GP ensure your supplement plan matches your unique needs and surgery type.

How to Protect Yourself

1. Don’t take your vitamins before a blood test.
   It can give falsely high readings. Always test on an empty stomach without supplements that morning.

2. Read your labels carefully.
   Look for hidden B6 (pyridoxine/pyridoxal). Check for duplicates across products.

3. Bring everything to your next appointment.
   Dr South suggests literally bringing your supplement bag to show your care team. “I go through it with a fine-tooth comb,” she says.

4. Stick to trusted, research-backed brands.
   Choose products that publish clinical data and meet international bariatric guidelines.

5. Don’t assume ‘natural’ means safe.
   Concentrated nutraceuticals can act like drugs—stronger than anything you’d get through food alone.

What’s Being Done About It?

The TGA introduced warning labels for products exceeding 50 mg of B6 in 2023, but advocates—including Dr South and the RACGP—say it’s not enough.
They’re calling for tighter controls, clearer labelling, and stronger collaboration between food and supplement regulators.

Until then, awareness is key.
If you experience numbness, tingling, or unexplained weakness, ask your GP for a B6 test. Early detection can prevent permanent nerve damage.

Final Thoughts

“I’d hate for people to stop taking supplements altogether,” says Dr South. “Bariatric patients do need them—just the right ones, in the right amounts.”

At BSA, we couldn’t agree more.
Empower yourself with information, keep up your regular bloods, and talk openly with your care team.
Your health journey is unique—and so should your supplement plan be.

Listen to the Full Episode

🎧 The Bari Chronicles – Season 4 Episode 1: ‘Multivitamins, B6 and the Truth About Supplements’
📅 Full episode out Monday 20 October 2025
📍 Available on Spotify, Apple Podcasts and