Hey sis, good question! So true na some vitamins can interfere with each other, like iron is best taken on an empty stomach and away from calcium kasi hindi sya mabilis na-absorb, so most doctors suggest spacing them out by a few hours. Best to ask your OB directly about the timing since siya ang nag-prescribe, pero usually iron in the morning, calcium later in the day or before bed, and fish oil with meals works well para sa maraming moms na kilala ko.