It comes after Mr Swinney shared a graphic on Monday about the risk of Covid transmission in various conditions of mask-wearing and social distancing.
The Scottish Government later admitted he did not know the source of the graphic or whether the information shared was correct.
Asked to confirm that Mr Swinney’s advice was accurate, deputy chief medical officer Dr Nicola Steedman was unable to do so and said the issue was “incredibly complex” and “the degree of protection is variable depending on on the mask and on the distance from the person”.
The graphic listed percentages of risk of transmission in different scenarios, but did not give any information about the type of mask used or whether the subjects were indoors or outdoors.
It was created at least a year ago and does not specify which variant of Covid-19 it refers to.
Mr Swinney has not deleted his Twitter post or alerted his followers the information shared may not be correct.
The First Minister defended Mr Swinney’s actions, saying people “should not lose sight” of the message he was trying to get across, that masks are in general beneficial in preventing Covid spread.
But ministers will “reflect” on the need to share verified Covid information in future, she said.
Asked if his actions were acceptable, Ms Sturgeon told a Covid briefing on Tuesday: “The Deputy First Minister tweeted an image yesterday that was intended to illustrate what is absolutely the case, that wearing face masks protects people from transmission of the virus.
"So if I wear a face mask it gives you some protection, if you wear a face mask it gives me some protection.
"He was illustrating that point, and I think the more we can illustrate that point the better.
"What I’ll say in addition to that is I think we recognise that in seeking to illustrate that we should take care to use properly verified graphics, and we’ll certainly take that on board in terms of how we tweet that information in future.
"But getting the general point across, he is absolutely right to seek to do, as I seek to do that on a general ongoing basis.”
Asked if Mr Swinney’s figures were "scientifically accurate”, Dr Steedman said: “It all depends on the type of mask.
"Some of the information which I believe went into that particular infographic was a mixture of information from real world infection studies, but also experimental studies of coughing bits of virus in the air and seeing whether certain masks stopped it.
"Face coverings are different from surgical face masks, so it's incredibly complex. I think that figure was an effort to simplistically represent the fact that masks and face coverings do provide some protection. The degree of protection is variable depending on on the mask and on the distance from the person.
"Because it's so complex, there’s a lot of very simple infographics out there that try very hard to get that message across, so I understand that, but actually what's underneath it is very complex.”