Leaders and nonprofit organizations took to Twitter to mark World Health Day and toast the WHO, whose constitution was enacted April 7, 1948, to affirm its mission as the “directing and coordinating authority for health within the United Nations system.” 

These groups included the Kenyan Red Cross, Grand Challenges Canada, the Cleveland Clinic and the International Diabetes Federation, among others.

The U.N. itself also chimed in, with Secretary-General Ban Ki-moon urging civic and private leaders to devote “attention and resources to ensuring that people everywhere have the chance to grow older in good health.”

 By 2050, the WHO estimates that there will be almost 400 million people age 80 and older — compared to about 14 million people in that age group around 1950.”Older people make many valuable contributions to society — as family members, as active participants in the workforce and as volunteers within communities. The wisdom they have gained throughout their lives makes them a unique resource for society,” Ban said in a press release. But more older people also means an increased demand on health care and social security systems.”