New Zealand Listener – August 03, 2019

LISTENER AUGUST 3 2019

Bit on

the side

People on a common

diabetes medicine may

need extra vitamin

B12 because of a side

effect of the drug.

Question:

Is there a link between the drug

metformin and vitamin B12 levels? I ask

because my GP gives all her patients on

metformin three-monthly injections of

the vitamin.

Answer:

U

se of metformin, the

mainstay treatment

for type 2 diabetes, can

indeed lead to a vitamin

B12 deficiency.

More than 240,000

New Zealanders have

diabetes, many of them with type 2,

a condition in which the body’s cells

have become insulin-resistant or the

body doesn’t produce enough insulin

to keep them healthy. Metformin

has been the frontline treatment

for years, along with recommended

changes in lifestyle and diet. The drug

is taken as a tablet that reduces the

amount of glucose the liver releases

into the blood. It also helps the body

to respond better to insulin and move

glucose into body cells as needed.

But like most medicines, met-

formin has a number of side effects,

including the potential to lower

vitamin B12 levels. Given that a B12

deficiency can cause progressive and

irreversible damage to the nervous

system, this is a significant downside.

What starts as a bit of numbness

and tingling in the hands and feet

can cause permanent damage to the

spinal cord and nerves outside the

brain.

That’s not all. Other symp-

toms include anaemia, fatigue,

by Jennifer Bowden

NUTRITION

THIS LIFE