However, the benefits of the transfusion therapy must be weighed against the risks of
excessive iron stores, transfusion reactions and the burden of missed work and school days.
Children make the conversion very poorly and infants not at all — they must obtain their precious
stores of vitamin A from animal fats — yet the low - fat diet is often recommended for children.2 Strenuous physical exercise,
excessive consumption of alcohol,
excessive consumption of
iron (especially from «fortified» white flour and breakfast cereal), use of a number of popular drugs,
excessive consumption of polyunsaturated fatty acids, zinc deficiency and even cold weather can hinder the conversion of carotenes to vitamin A3, as does the low - fat diet.
But overdoses of
iron - containing (ferrous sulfate) vitamin / mineral supplements, sudden liver damage that releases
stored iron,
excessive blood loss, hemolytic anemias and bone marrow disorders have all been associated with high serum
iron levels.