Soybeans have very high levels of a form of phytic acid that is particularly difficult to neutralize. As early as 1967, researchers testing soy formula found that it caused negative zinc balance in every infant to whom it was given. Scientists have found a strong correlation between phytate content in formula and poor growth, even when the diets were additionally supplemented with zinc. High amounts of phytic acid in soy foods and grains have caused retarded growth in children on macrobiotic diets. A reduced rate of growth is especially serious in the infant as it causes a delay in the accumulation of lipids in the myelin, and hence jeopardizes the development of the brain and nervous system.
Soy formula can also cause vitamin deficiencies.
Soy increases the body s requirements for vitamin B12, a nutrient that is absolutely vital for good health. Early studies with soy formula indicated that soy blocks the uptake of fats. This may explain why soy seems to increase the body s requirements for fat-soluble vitamin D. Aluminum content of soy formula is 10 times greater than milk based formula, and 100 times greater than unprocessed milk. Aluminum has a toxic effect on the kidneys of infants, and has been implicated as causing Alzheimer s in adults. Studies indicate that allergies to soy are almost as common as those to milk.