I'm Taking Iron Tablets To Raise My Ferritin Levels Up

I'm taking iron tablets to raise my ferritin levels up to the 90 to 120 range. I've read that it needs to be that high for hair growth . I should say I'm hypothyroid. Have had issues with hair loss since I was In my later teens. I have been taking one tablet 300 mg, of iron, and was wondering if taking two would be better. I've seen some regrow th but not in all areas yet.