Your distribution from a traditional IRA in any year affects subsequent distributions only to the extent that there may be a lower balance in following years. (Although that depends on the interest/dividends/appreciation of the funds remaining in the account.)
The required minimum distribution is calculated anew each year. There are two factors:
1) The balance in the IRA account (or accounts if more than one) on December 31 of the prior year.
2) Your life expectancy from the IRS life expectancy tables.
Divide #1 by #2 and that is the RMD. Your IRA custodian should be reporting the RMD to you. Of course, you are free to take more than the RMD if you desire.
You might want to take a look at IRS Pub 590: (especially beginning on p. 34)
"Look, sir, we can't just do nothing."
"Why not? It's usually best."