In India, Its pretty easy to get various preventative tests done. As for as prices, its cheap enough for engineers but non-trivial sums for a majority of the population.
As an example here's a list of all the tests, prices that a diagnostic center chain in South India provides https://appointments.aarthiscan.com/#/city/Bangalore/select-... https://aarthiscan.com/test-package/preventive-health-checku...
The test for Vitamin D is about 16EUR and comprehensive blood screening starts at 18EUR