caffeine-free Green Tea at work in the morning...

Completely freaked out.  I'm 4 weeks ... it's winter in NY and I'm always cold!  For the last week I've been having a cup of hot green tea (caffeine free) when I get to work in the morning. I'm nervous because I've read that you shouldn't drink green tea due to it messing with the absorbtion of Folic Acid.  I take my prenatals at night (have to take thyroid meds in the AM). So I guess my body would be absorbing it over night?? I'm obviously going to stop drinking it all together. I am terrified of birth defects ugh 😰