Is it possible to create artificial gravity by magnetizing iron in the blood stream? I have been thinking is it possible that using a rather strong magnet on the human body's blood stream we could enact a small case of artificial gravity on the human body via the iron in the hemoglobin in the blood stream. 
There are 4 Problems currently with this theory:


*

*The could be residual effect on the human body 

*No one has ever tried to affect the blood stream directly using a powerful magnet

*Can we create an electromagnet or a non normal magnet to cause slight magnetization but only of the feet and legs to ensure no abnormal strain is placed on the heart

*If the iron in the blood is magnetized so will every other magnetic metal item on board such as tools or weapons

 A: Short answer: No.
The iron in the body is not magnetic because it is not in metallic form nor magnetite form. It is instead an ion complexed to nitrogen atoms in turn bonded to proteins.
The human body repels magnets very slightly because it has water, which is diamagnetic. Powerful enough magnets have been used to make frogs float, but unfortunately only small objects can be levitated this way.
Diamagnetic materials will seek out regions of lower field strength. The diamagnetic acceleration goes as B*dB/dx, where B is the magnetic field and dB/dx is the gradient. Larger objects need more total B because the B gradient must persist over a longer distance. Because the force is B*dB/dx and not dB/dx, the maximum B required follows a square-root field strength scaling law. For a human, ~25 times larger than a frog, you will need a field 5 times as intense. Ten tesla will levitate a frog, so 50 to for a human. 45 is our limit (national high magnetic field lab) for now. It requires megawatts of power for the resistive inside, liquid helium for the superconductive outside, and probable lots of care to make sure the whole thing doesn't explode due to the magnetic forces. In the future, it is not infeasible that we will produce 50 tesla, but it would probably have a small bore/coil size ratio.
Far more important is that 10 tesla MRI will make a person quite dizzy. The vestibular system (ear motion detector) runs a DC electric (ionic) current through a fluid. If you put this in a static magnetic field, you will get a Lorentz force, which will swirl the liquid. If you rotate in the field, other magnetic effects on conductors would apply as well. 50 tesla would be much harder, if not dangerous. 
The shape is also important. You would need to build a static machine so that you can sit or stand in the "gravity", but you can't walk around. 
Finally, your magnet would attract ferromagnetic projectiles with 25 times the force of a 2T MRI. Shrapnel!
Lets stick to rotating space stations for now.
