Gravity has only one direction, and there is no gravity anti-charge, so there isn't a shield of ANY kind for gravity. Electric force that in turn gives origin to magnetic forces has two opposite directions, depending over the type of charges, which Nature offers in exactly two varieties, therefore we call them /positive/ and /negative/. The true geniuses were Sir Isaac Newton (England) and Sir James Clerk Maxwell (Scotland). The intensity of the magnetic force is very very weak on Earth when compared to the Earth's gravity field; moreover a living body is (usually) electrically neutral, and does not contain electric currents inside (save for very weak neuronal and heart beat currents), therefore it will be almost completely neutral to the Earth's magnetic field. The answer is therefore also related to comparison of quantities (comparison of the strengths of the forces or of the related fields). Don't give up making questions, they are an exceptionally good ground for learning, especially at your age (not so many boys and girls want to understand deeply!), but if you want the true answer, there should obviously, as you already know, be some hard study to do. I still remember my unanswered question related to Physics as a boy; the answers came much time later, which thing I don't wish you. Greetings, Andrew

I seriously hope you are just kidding here. I am in the Philippines right now, and most people here are well educated. Come on! Gravity does not work like magnets. Magnetic energy and gravitational energy are two very different things.

Are you fukin kidding me? http://en.wikipedia.org/wiki/Gravitation

Are you confusing gravitational force with the magnetic force from the poles? Go read more. Please. I agree with Eliot; I've met Filipinos and most are smarter than this.

Actually, iron, cobalt, copper, manganese, molybdenum, and zinc are required nutrients for human survival! That's probably not why we're affected by gravity; I can't give you a satisfactory answer, but we do require certain metals in our diet to survive. :) For instance, an anemic person lacks iron in his/her blood.