Your whole claim was referring to DC, now you suddenly want to compare to AC. I'll go along with it.

Ignoring the skin the internal resistance of the body is very low, likely 100's of ohms per meter. Vdc only needs to be sufficiently high enough to break over the skin's resistance (300 to 100K) in two locations to conduct current through the body. Though if you want to get really into it there is capacitive charging and absorption currents that occur at t=0+. The capacitance plays very little role in a DC circuit.

The skin's capacitance is high compared to the internals, it makes a decent low voltage insulator when dry and free of contaminants. In an AC circuit the skin's resistance is far lower than the capacitive reactance making the capacitance an unlikely contributor to a current inside the body. Same with the internal resistance and reactance but the reactance has slightly more of an effect compared to the skin.

Your base claim was "DC can not harm a human body", which Yes it can easily send a current through the body if the voltage is high enough to break over the dielectric strength of the skin.