I've posted about this a lot, so I'm sure everyone already knows what I'm going to say.
I've had hypothyroid symtoms for a long time (around a decade), but when I went low carb paleo/primal my symptoms got significantly worse.
1) In the shower, I started losing handfuls of hair.
2) I developed a chronic low grade depression with periods of extreme mood instability and anxiety attacks
3) My cold sensitivity got worse
4) I developed an extreme fatigue that made normal daily chores impossible
5) My normally low body temperature got so low that I was practically a corpse
6) I gained extra fat while eating very few carbs and restricting calories to 1,200-1,400/day
I'm sure there was more, but those are the symptoms that come to mind immediately. Supplementing with iodine, taking vitamin D and cod liver oil and liver did nothing.
I switched my diet to be more in line with the Perfect Health Diet, which is also an ancestral diet but promotes eating higher levels of healthy starches + carbs, and added a few Ray Peat tweaks (more organic sugars, salt, and less muscle meat, pregnenalone and DHEA supplementation) and Cold Thermogenesis (cold showers, ice baths, spot icing).
My hypothyroid symptoms started improving pretty quickly after making these changes, and I continue to steadily improve. I test my body temperature almost daily, and it is slowly increasing.My fatigue has been decreasing so that I'm now able to do yoga and walk 1-2 hours daily, and I'm not losing handfuls of hair in the shower anymore and there is quite a bit of new hair growth. I overall feel better, and I'm actually slowly losing the extra fat I gained by eating primal high fat/low carb.