Upvote:6
There is this recent study:
Jackson et. al. Disequilibrium, Adaptation, and the Norse Settlement of Greenland
Under "Cultural Contact" they write
"Little is known of the possible interactions between either the Dorset Paleo-Eskimo or the later Thule Inuit and Greenland Norse, and hostilities mentioned in the Vinland Sagas and Ivar Bardarsonβs accounts remain ambiguous and uncorroborated in the archaeological record ... A recent large-scale genetic study of the modern Greenlandic population found no evidence for any admixture with Norse or Dorset populations and argues for a single, substantial migration event ..."
DNA studies, for example based on ancient DNA
Raghaven et. al. The genetic prehistory of the New World Arctic
and on DNA of contemporary population
Moltke et.al. Uncovering the Genetic History of the Present-Day Greenlandic Population
found no evidence of geneflow between the Norse and the Dorset or later Inuit (though they were able to reconstruct the Inuit colonization), thus adding to the picture mentioned in the cited paragraph.
I would like to add: written or other wise traded testimony may be treacherous. As long as there is no archeological evidence there will be no certainty, but at least there is no genetic evidence of deeper contact.
All in all and because of missing evidence I would say: no, Vikings did not cause high mortality, neither by epidemics, nor by conflict.
The situation in high medieval times is not really comparable to the later "conquista" of Central and South America.