Plant-Based Diets: Important Nutrients to Watch Out For - Preventing Dementia

I had several reasons for starting a vegan lifestyle, but one of the most frequently asked questions when I switched to a completely plant-based diet was how I would obtain the nutrients I previously got from meat.  This is something I've always pondered myself.


By going plant-based, I started getting more vitamins from vegetables, and necessarily started cooking from scratch more often, reducing my intake of additives. As I mentioned in a previous blog post, I've felt my constitution change as my gut environment changed. However, it's also true that there are certain nutrients that are more abundant in animal products.


One of these is vitamin B12.


Vitamin B12 is essential for the formation of red blood cells and the normal functioning of the nervous system. A deficiency in vitamin B12 can lead to health issues such as anaemia and neurological disorders. As vitamin B12 is found abundantly in animal foods like meat, fish, eggs and dairy products, vegetarians and vegans need to be mindful of their intake.

For vegans, it's common to take vitamin B12 supplements or fortified foods to meet their needs. Options include cereals, plant-based milks or nutritional supplements fortified with vitamin B12.


One of my clients mentioned that her mother had developed Alzheimer's-like symptoms that persisted despite visiting many hospitals. It wasn't until the last one suggested a vitamin B12 deficiency that adding a B12 supplement made those Alzheimer's-like symptoms disappear completely.

Upon researching, while the relationship between vitamin B12 and Alzheimer's disease is still being studied without definitive conclusions, some intriguing associations have been noted:


Neuroprotective effects:

Vitamin B12 is one of the essential nutrients for nerve function and brain health. A deficiency may cause nerve cell damage, potentially increasing the risk of neurodegenerative disorders like Alzheimer's.


Link to homocysteine:

Vitamin B12 is needed to metabolize a compound called homocysteine. High levels of homocysteine are thought to potentially damage brain blood vessels and increase Alzheimer's risk. B12 deficiency may promote homocysteine accumulation. 


Maintaining cognitive function:

Vitamin B12 also plays a role in maintaining cognitive function. Thus, a deficiency may be associated with cognitive decline and increased dementia risk. As Alzheimer's is a form of dementia, vitamin B12's role relates to this.


While these links aren't fully understood yet, adequate vitamin B12 intake does seem important for brain health.


For me, while I found some plant-based foods containing B12, the amounts weren't sufficient, so I supplement with a vegan B12 vitamin. When taking supplements, I try to optimize absorption.

Having seaweed or seaweed products (like nori sheets), fermented foods (like natto or miso), and plant-based milks (like almond or soy milk) together can aid vitamin B12 absorption. Dishes with soy and mushrooms (shiitake, enoki, etc.) can also help - for example, a tofu soup with mushrooms, or a miso soup with mushrooms contains plant foods that promote B12 absorption.



Obeid, R., & Herrmann, W. (2006). Mechanisms of homocysteine neurotoxicity in neurodegenerative diseases with special reference to dementia. FEBS Letters, 580(13), 2994–3005. PubMed

Clarke, R., Smith, A. D., Jobst, K. A., Refsum, H., Sutton, L., Ueland, P. M., ... & Collins, R. (1998). Folate, vitamin B12, and serum total homocysteine levels in confirmed Alzheimer disease. Archives of Neurology, 55(11), 1449–1455. PubMed

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