I take it year-round and it was 35-degree summer here so I'm sure you'll be fine (I did a blood test and I was still in the range I like to be in, not crazy high)

btw, try k2 + d3 drops, usually, they are sold together and by combining them you get optimal calcium metabolism (D3 increases calcium availability, and K2 ensures its proper utilization and storage in bones while protecting arteries and other tissues).

good book on it here
https://www.amazon.co.uk/Vitamin-K2-Calcium-Paradox-Little-Known/dp/0062320041/ref=tmm_pap_swatch_0?_encoding=UTF8&sr=8-1

i might do a review on it here at some point because i don't suspect many people will want to read a whole book on it (although actually quite an interesting story behind its discovery)