While the phrase "Thank you for the concern you have had for me" is grammatically correct and understandable, it sounds a bit formal and might not be the most natural way to express gratitude in everyday conversation.
A more common and natural way to say this would be:
"Thank you for caring about me."
This phrase is simpler, more direct, and commonly used in English to express appreciation for someone's concern and care. It maintains the essence of the original expression without sounding overly formal or complex.