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PCOS, Metformin and B12

Metformin is a well-recognised traditional medical drug given to improve insulin sensitivity in PCOS sufferers. However, taking Metformin may affect the absorption of the vitamin B12. A medical study showed that women on high doses of Metformin were at risk of lower serum levels of B12.

Vitamin B12 (cobalamin) - is an essential vitamin, but one we can’t produce and so we must consume it through food or supplementation. Meat is a main source of B12 which is why it is particularly important for vegetarians and vegans to consider supplementation. 

What does it do and why do we need it?

  • Supports normal function of your nerve cells
  • Needed for red blood cell formation and may help prevent anaemia 
  • DNA synthesis
  • During pregnancy – may help the prevention of brain and spinal cord birth defects.
  • Plays a vital role in good bone health
  • May improve mood and depression as it is needed for the production of serotonin, our happy mood neurotransmitter!
  • May contribute to good brain health by preventing the loss of neurons. Deficiency has been associated with memory loss in older adults
  • Gives you an energy boost - involved in energy production in your body. 

What are the symptoms of B12 deficiency?

Anaemia which may manifest itself as:

  • fatigue
  • lethargy
  • breathlessness
  • feeling faint
  • headaches
  • pale skin
  • palpitations
  • tinnitus

Other Symptoms of vitamin B12 deficiency

  • Weakness, tiredness
  • Sore and red tongue 
  • Mouth ulcers
  • Nerve problems - pins and needles, muscle weakness
  • Disturbed vision
  • Irritability
  • Depression
  • Mental problems like depression, memory loss, or behavioural changes 

So, what are the food sources?

  • Organ meat e.g. liver
  • Meat
  • Eggs
  • Shellfish
  • Seaweed
  • Fortified foods e.g. cereals

As you can see it is vital that we support our B12 levels in PCOS. Making sure you diet is rich in these sources is crucial.

If you would like to chat more about PCOS and how you can manage the symptoms through diet and lifestyle please do contact me. Having suffered it myself I am so keen and passionate about supporting others. 


 B12  - Linus Pauling Institute. 

Esmaeilzadeh, Sedigheh et al. “The Effect of Metformin Treatment on the Serum Levels of Homocysteine, Folic Acid, and Vitamin B12 in Patients with Polycystic Ovary Syndrome.” Journal of human reproductive sciences vol. 10,2 (2017): 95-101







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