I don't think that it is that big of a deal, but I do think that you could fix it.
First unravel the stem(if possible) and then put more soil around the base of it, right up to the first set of leaves. Your stem is so small that it can not support the weight of the growth above it.
You need to get a fan on that stem to stregthen it and you may have to move your lights closer in order to stop the stretch.
i really would fix that loop though because while it is not a problem now, IMHO, I think that if not corrected it will become a problem as that stem gets bigger and more ridgid. And if it is not fixed now while the stem is still pliable it will be impossible to fix when the stem gets woody. you have to remember that this is like the lowest part of your stem, which will be the thickest, most ridged, and woodiest part of your plants.