|A deficiency in magnesium causes hyperplasia of the adrenal cortex, elevated aldosterone levels, and increased extracellular fluid volume. Aldosterone increases the urinary excretion of magnesium; hence, a positive feedback mechanism results, which is aggravated since there is no renal mechanism for conserving magnesium.|
In laboratory animals, a pyridoxine deficiency at the renal level decreases the kidneys' ability to secrete sodium. In addition, since pyridoxine requires magnesium for phosphorylation to its active form, a magnesium deficiency can lead to decreased B6 activity. Increased insulin secretion, in response to sugar consumption, results in sodium retention that is independent of aldosterone.