L ast week, I met a young man with cerebral palsy, hospitalised with an infection. Not capable of speaking, he lay quietly in his bed. Although he appeared settled, I had no way of knowing how he felt, so imagine my relief when his carer told me that, after 10 years, she could interpret his every expression.

“What do you think about IV fluids?” she asked. “It might perk him up a bit.” Under normal circumstances, I would have said yes.

Instead, I reassured her that he was not dehydrated, had perfect renal function and, if needed, we could administer more water through his feeding tube. I took this step amid a global shortage of intravenous fluids used to replace fluid losses, resuscitate patients and deliver essential medications including chemotherapy drugs, antibiotics and anaesthetics. Australia does not manufacture its own IV fluids and can’t compel companies to do more.

Hence, doctors are receiving daily reminders to save IV fluids for those who need them the most . Sign up for Guardian Australia’s free morning and afternoon email newsletters for your daily news roundup Even though I had used my clinical judgment, I felt discomfited by our interaction. Away from the bedside, I wondered if the carer thought I had denied my patient IV fluids because he was disabled and disenfranchised.

Maybe this is why I found myself reacting more strongly than I’d care to when I read about the latest health fad: the rise of intravenous vitamin cocktails for the worried well..