"They have caregivers or relatives who pick them up and take them at set times.
"It would be very hard to reorganise their whole life pattern to get to the supermarket at a set time. I don't think it is a particularly smart idea."
In the past 24 hours, there were 36 new confirmed cases of Covid-19, taking the nationwide total to 102 , the Ministry of Health announced.
Since the first case was confirmed in late February, supermarkets around the country had been working flat out as many people panic-bought.
It prompted the nation's supermarkets, Prime Minister and health officials to call for calm - to little avail.
People buying products until there were none left only "penalised" the elderly and rationing was a key way to sorting out the problem, Welch said.
"When the elderly get for their fortnightly trip, if the products are out of stock that means they go without for as much as a fortnight," he said.
"Human nature is greed, unfortunately, there's no nice way to put that and if people aren't going to self regulate, it's got to be by the provider."
To help combat this, Countdown supermarkets last week introduced limits on certain products to try and stop panic buying.
READ MORE: • Coronavirus: Four Auckland schools linked to Covid-19 in one day • Coronavirus: What alert level 3 would mean for you • Coronavirus: Front-line health workers and other medical staff want alert level 4 now • Coronavirus: Police Commissioner Mike Bush outlines response to Covid-19
It put limits of two items per customer on products such as packs of toilet rolls, hand sanitiser, personal wash, Panadol, wipes, pasta and rice.
Last week, Prime Minister Jacinda Ardern announced people aged 70 or over should not leave the house as they were at higher risk to the virus.
Meanwhile, people might not have spoken with their elderly neighbour, but Welch urged them to ask if they needed anything on their way to the supermarket.
"Knock on the door and ask if you can get something for them - you might make a friend, you might save a life," he said.
"You've got to do whatever you can, offer help wherever you can, think about your elderly relatives.
"The other thing is for families, to get on that telephone and talk to nana and grandad, some of them are going to feel pretty isolated."
VirusFacts2