Vitamin D supplements are highly recommended for people located at higher latitude areas. (theveganlife.com)
However, even just 1 degree warming was huge in high latitude areas where polar amplification is occurring (early Jan 2006 post at RC). (realclimate.org)
By the way, HadCrut underestimates current warming because it omits high latitude areas that have warmed the most. (deepclimate.org)