A 3 - year trial in 244 postmenopausal women found that those taking vitamin K2 supplements had much slower decreases in age - related bone mineral density (15). (healthline.com)
I will quote from NASA / GISS: the «overall slow decrease of upwelling SW flux from the mid-1980's until the end of the 1990's and subsequent increase from 2000 onwards appear to caused, primarily, by changes in global cloud cover (although there is a small increase of cloud optical thickness after 2000) and is confirmed by the ERBS measurements.» (judithcurry.com)
Severe dehydration (such as can happen with gastrointestinal illness) can cause a sudden and drastic drop whereas a slow decrease in milk volume is more typical of illnesses such as the flu. (theleakyboob.com)