You shouldn't have to worry about calcium in particular given that LSPI seems to be an issue primarily in turbo direct injection engines (like the one in my FXT, which was recalled due to LSPI).
There is a lot of speculation that intake valve deposits in GDI engines can be lessened by using oils with low NOACK loss and low Sulfated Ash, Phosphorus, and Sulfur (SAPS). I honestly don't know if there have been any studies that show that this is really the case. Low SAPS oils will necessarily have to have reduced levels of ZDDP, which is an important anti-wear additive that contains phosphorus and sulfur. An extreme example of a low NOACK, low SAPS 5W30 is Mobil 1 ESP, which has a NOACK loss of about 6.5% and 0.6% SAPS (regular M1 5W30 is about 10% and 0.8%, respectively). The ESP oil also has a reduced detergent level that makes it less than suitable for long oil change intervals in the US, its real design target was for European diesels using low sulfur fuel...a low detergent oil will have a low Total Base Number (TBN) that reflects a lower capacity for neutralizing acids, IIRC the TBN for M1 5W30 is just under 10 and it's between 6 and 7 for the ESP flavor. For whatever reason, the 5W30 ESP has about the same dose of calcium-based detergents as regular M1 5W30 but almost none of the magnesium-based detergents of the latter...I have no idea why that is the case.