Antacids, supplements with calcium, iron, magnesium including vitamins, interefere with levothyroxine absorption if taken within about 4 hours of taking levothyroxine. This does not mean it totally negates your hormone pill, just that less of it will be available to your body. This time frame is a guideline. You should refrain from drinking or eating anything except water within one half to one hour after taking levo. Supplements or vitamins have a lot more calcium than milk on cereal or in coffee so after 1/2 to 1 hour, you eat breakfast, have coffee with cream, cereal, etc. You will hear of other foods that may interfere with absorption, but do not get wrapped up in all that. Dosing levo does not occur in a vacuum. Some days your body may require more or less hormone than others, just like when you had a thyroid. Fortunately, the half life of levo is a week. This means it takes a week for half of the first dose to clear your body. Thus it hangs around a long time, easily accommodating any little variations in your requirements or absorption. I eat whatever I want after about 30 minutes in the morning, but take my calcium supplement with dinner. I take Pepcid if I need an antacid as it does not interefere with absorption. In a very short time, you will not even think about it. I have been taking it for five years. Due to the long half life, if I forget a pill, I just take two the next day. If I accidentally take a second pill, I just skip the next day. In reality, you could take a weeks worth all at once and they actually do this for patients who cannot be relied on to take a pill every day. So relax, you’ve got this!