Growing evidence suggests that too much folic acid could be a bad thing for patients, Professor Tim Spector has told delegates here in Darwin.

Speaking during a session on genetics and epigenetics Professor Spector, who heads up the genetic epidemiology department at the Kings College in the UK, told delegates he had recently come to the realisation that some vitamins have a double-edged sword.

“Just because it’s called a vitamin we don’t bother thinking about it – if they were called ‘drugs’ we would have a toxic range,” he said.

There was increasing evidence that too much vitamin D can up the risk of fractures and falls; calcium had also been linked to heart disease.

“There’s this blanket idea that we give this stuff out and the only thing we need to do is make sure that they take it –  without realising that for some people a threshold might be important” he said.

“We need to start thinking about that seriously and perhaps work out some proper ranges”.

Too much folic acid was also a concern, and women, particularly in the US, were taking too much of it.

“Folate is really important for changing the methylation epigenetically and this is having, certainly in animals and possibly in humans, some effects of increased infertility and cancer… we need to be very careful,” he warned.

During the question time following the session co-chair Professor Lyn March noted that most patients taking methotrexate were also taking folate supplements.

“We often see quite high red cell folate levels…we also see a potential association with melanoma that we thought was due to the methotrexate…but maybe it’s to do with the supplemental folic acid?” she said.

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“We need to look at this more carefully and it could be that we start tailoring folic acid on more on a personal way rather than treating them like smarties,”Professor Spector replied.