2. ‘Vitamin B12 – A Component
in Health & Disease’
• Vitamin B12 Function
• Biochemical Assessment
• Absorption
• Food sources & Requirements
• Vitamin B12 Deficiency
• Vitamin B12 and Neural Defects
• Vitamin B12 and Cardiovascular Disease
• Vitamin B12 and Cognitive Decline
• Vitamin B12 and Osteoporosis
3. Vitamin B12
• Also known as cobalamin
• A water-soluble vitamin
• An essential nutrient for human growth and cell development.
• Only found in foods of animal origin:
• E.g. beef, lamb, liver, fish, dairy products
• Also found in fortified foods e.g. cereals and fortified plant-based products.
• Supplements
• Adults (19-64yo) need about 1.5 microgram a day (British
Nutrition Foundation).
• Vitamin B12 deficiency most common in elderly, also
vegetarians and vegans.
• Vitamin B12 deficiency is elevated MMA & tHcy levels which
can be related to neuropathy , also diseases including
cardiovascular disease and osteoporosis.
4. Why did I choose this
topic?
• Vegetarian and vegan diets
• ‘Veganuary’
• Climate change
• Prevalence of B12 deficiency in the UK (estimated)
to be around 6% in people under 60 years and closer
to 20% in people aged over 60 (NICE.org 2014)
5. Why did I choose this
topic?
Human Biology
@SHU
MSc Dietetics
@SHU
Become a practising
Dietitian
‘Many dietitians are involved in highlighting and driving demand for nutrition and
dietetic services across the UK, demonstrating why these services are so vital to the
health of the nation … It is important to be able to clearly understand nutrition and
dietetic services available and their positive impact.’
Editor's Notes
Also known as cobalamin
A water-soluble vitamin
Vitamin b12 is absorbed by peptic activity in the hydrochloric acid in the stomach before passing into the small intestine where b12 is then co-absorbed with intrinsic factor. Then it passes across the distal ileum and released into the bloodstream
There are different forms of B12 including methylcobalamin which have their own potential biological activity. Vitamin B12 is an essential nutrient linked to human growth and cell development and crucial for red blood cell prod. And dna synthesis. B12 is an important component of several enzymes and is involved in the metabolism of certain amino acids. It is also necessary for neurological function as it is involved in the development and maintenance of myelination of the central nervous system.
Only found in foods of animal origin as the vitamin is concentrated in animal tissue. In the animal B12 is synthesized by bacteria in the GI tract and is then absorbed upon consumption.
E.g. beef, lamb, liver, fish, dairy products
Also found in fortified foods e.g. cereals and fortified plant-based products.
Supplements
Adults (aged 19 to 64) need about 1.5 microgram a day of vitamin B12.
Vitamin B12 deficiency, caused due to malabsorption of the vitamin or simply not enough in the diet is most common in elderly, also vegetarians and vegans who consume little or no animal products.
Vitamin B12 deficiency can be defined as elevated levels of B12-dependent metabolites: methylmalonic acid and homocysteine (tHcy). In turn, these elevated metabolites can be related to disorders associated with oxidative stress such as neuropathy and diseases including cardiovascular disease and osteoporosis.
Eg in terms of osteoporosis, Vitamin B12 is important for bone health as it plays a vital role to increase and influence osteoblastic proliferation, formation and function (Melton & Kochman, 1994). When an individual is deficient, the increased level of MMA and tHcy which stimulates osteoclastogenesis, suggesting B12 deficiency indirectly increases osteoclast formation, and in turn bone degradation leading to bone loss and fractures.
I feel like this topic is very appropriate now as more and more people turn to meat free diets as they become more conscious of the consequences that their food choices could be having on the state of the environment and climate change.
Vegans in particular follow a strict plant-based diet with no products from animal origin, therefore as B12 is not naturally found in plant-based foods they are a higher risk group of not getting the right amount of B12 they need and as a result could develop a deficiency.
Also as a vegan myself its good to expand my knowledge on just how important B12 for the functioning of the body and make myself think whether I am getting enough in my diet.
The latest figures I could find were from 2014 so a few years ago now but its estimated the prevalence in the uk is about 6% in under 60s and up to 20% in the elderly over 60. Considering the impact and consequences that vitamin b12 deficiency can have on the functioning of the body and its relation to neuropathy, cardiovascular disease and osteoporosis, these figures are very substantial.
Dietetics is what I want to go into after uni so I’ll hopefully be doing a masters here.
I am intrigued to learn more about and then help others understand and utilise food as a medicine for the prevention and management of disease.
And as I have already done my review for human nutrition module on fibre and the health benefits of that and now this I believe I have demonstrated how my interest centres on nutrition and diet and how it can be used to promote health and manage certain disorders and conditions such as B12 deficiency.
I am motivated to influence the eating behaviours and food attitudes of individuals for the greater good of their health and wellbeing, with the potential to positively impact those around them.
