Jackfish livers contain high levels of vitamin A. ((Submitted by Dave MacDonald))

Health officials are asking people in Saskatchewan's north to limit their indulgence in a seasonal delicacy — jackfish livers.

Jackfish livers, roasted or fried, are a popular northern treat and the fish are plentiful around spawning time on the Garson River in northern Saskatchewan.

Earlier this month, however, officials issued a warning saying that too much jackfish liver can lead to a vitamin A overdose. The problem has cropped up every spring for several years, they say.

According to Wynyard-based family physician Dr. Dale Dewar, the symptoms of hypervitamosis can be extremely unpleasant.

"The skin seems to be peeling off," said Dewar, who is the heath columnist for CBC Saskatchewan's Blue Sky radio program. "People can become quite ill with headaches, dizziness, blurred vision, loss of muscle co-ordination."

"If it's long term, then there are other things like osteoporosis and coarse bone growth."

While there are no guidelines telling northerners how much jackfish liver is too much, they are being advised to eat it in moderation, she said.

Pregnant women, in particular, are urged to be careful about how many livers they eat, because the vitamin overdose can affect their unborn children, according to James Irvine, medical health officer in northern Saskatchewan.

It's a particular chemical configuration of the vitamin — vitamin A2 — that's in the fish livers, Irvine said in a letter to La Loche health officials.

However, standard tests don't detect it, so some people with symptoms might show they have normal levels vitamin A levels, he said.

Usually  the  symptoms  go  away  on  their  own  without  medical  attention.