We each carry around in our brain a vast back-catalogue of things we’ve learned, extending all the way back to our most introductory units. Yet it’s exactly this oldest of material we probably mentally reach for & rely on it every day! Ahhhh those fantastic foundational classes 💓 When we were taken by the hand of our wonderful lecturers & introduced to each & every medicine on its own terms. In a delightfully dedicated way, unlikely to be repeated ever again under our own steam. Because as a busy nat/nut/herbalist or IM GP, how many days see you running fresh out of that precious commodity – ‘steam’?

And poor old – literally, given our great dame, Thiamina, celebrates her 100th birthday this year! – vitamin B1?!
Chances are she was the very first micronutrient we covered, in class 1, Nutrition 1, year 1 😶
That’s the year 1991 for me how about you??🦖

So, as a general rule, we haven’t undertaken a review or updated our information on essential elders like this…unless something has forced our hand. A patient, a presentation, a piece of research that gets the public’s attention, occasionally a new product perhaps? For me with B1, it was first in response to several paraesthesia presentations. I was stunned to read how suddenly these might appear at the hands of inadequate B1 and how quickly that B1 issue had appeared as a consequence of any number of patterns of food restriction, e.g. a recently-turned vegetarian adolescent, an individual on a health kick and intentionally losing weight but still with a high BMI, low histamine/FODMAP combo in someone with EDS. The second nudge? Going back to quantitatively analysing patient diets, where over & over again people who are eating enough & making good food choices fail to consume even its RDI!!🤯 Maybe the third thing, not so much as a nudge as a 2X4 across the head, reading the review by Marrs & Lonsdale, titled Hiding in Plain Sight: Modern Thiamine Deficiency, in which they eloquently articulate the ‘why’ – why this vitamin is so vulnerable and why now, alongside an explanation as to why we all keep missing this micronutrient issue!!! This is an essential read to update your understanding of B1 because lemme tell you, my dusty ol’ files on this fine dame were a little out of date!

Something along the lines of:

Alcohol is Enemy numero uno!

Polished rice & raw fish – an issue if over-consumed

Deficiency can be deadly…Beriberi both ‘wet’ and ‘dry’..? bit of doubt starting to creep in~!

Sumthin’ sumthin’ about energy pathways, pyruvate, lactate an’ all that jazz… 🙄

Yours too? Yet this is not an accurate understanding of, what has turned out to be, an essential vitamin more vulnerable than most. And increasingly so across the last few decades – not just according to Australian, but much international data from similar food-secure countries, to boot! But without an updated & more in depth understanding about thiamine, we don’t know what we don’t know and, accordingly, we’re missing so much! I guarantee we’re missing this deficiency in our practices. And we’re missing the opportunity to also get better results in our patients by addressing concurrent B1 issues when they present with a range of conditions from CHO intolerance to dysautonomias & beyond. We’re missing it because we think, ‘I’ve got them on a B complex or a multi or a prenatal – so it can’t be B1!’ Look again! 👀 We’ve had extraordinary feedback about our recent deep dive into the lovely, Thiamina. People all over the place screaming at us , ‘OMG THIS!’ While we all seek comfort, we need to keep checking whether being comfortable serves us entirely or not. Old comfy socks and track-dacks on at home? Absolutely. Accepting outdated, even antiquated, knowledge about our essential micronutrients…no.

The B1 Casualties Hiding in Plain Sight

​In Part 1, we explored why thiamine (vitamin B1) finds itself caught in the crosshairs of modern dietary trends, from ultra-processed, carbohydrate-heavy diets to grain-free, ketogenic and GLP-1-assisted eating patterns.

In this second instalment, we turn our attention to the casualties.

Long before beriberi, B​1 deficiency often presents as something far less conspicuous​ – a constellation of symptoms that many practitioners encounter every day.​ Drawing on classic depletion studies, modern clinical research and the physiology of energy metabolism, we examine what ​B​1 insufficiency actually looks like in practice, why it is so easily overlooked, and which patients are most likely to be walking the metabolic tightrope without realising it.​ We’ll explore the overlap between ​i​ts deficiency and conditions commonly labelled as dysautonomia, chronic fatigue, functional disorders and unexplained symptom complexes, before discussing an evidence-informed approach to assessment and repletion.​ Along the way, we’ll tackle some of the controversies surrounding thiamine supplementation, including benfotiamine, high-dose protocols, the role of magnesium, and why a generic B-complex may not always be the most rational response to a suspected B1 problem.

​This is an important discussion about one of the smallest nutrient reserves in the human body​ and one of the largest blind spots in modern clinical practice.