I have heard that eating foods which contain magnesium and calcium can help one get pregnant with a girl? Is this scientifically true or an old wives tale? Can somebody help?

I'be heard and read about studies reagrding the “gender diet”. Apparently a specific diet can change the pH level (how alkaline or acidic) in a woman’s body and thus changing the polarity of the egg. Apparently, by ingesting the suitable ratio of minerals, a woman can alter her uterine environment making it more conducive to attract either and render the survivability of an x or y chromosome from a sperm. Magnesium and calcium are 2 minerals that supposedly make the conception of a girl easier. Don't know anyone who have tried this method and conceived a girl though so can't vouch personally for this method.