I think you can go straight to boron; but it is much more expensive; you will need 10-20 capsules to reach 30-60 mg
Borax is inexpensive; can be taken in water (taste flat but not really bad ; I used to put a drop or two of lemon in the water ) Remember 1/4 of a flat teaspoon daily in water or with water if you make capsules.
A wonderful scalp cure if you suffer from dandruff or itching or similar;
Saturated borax with distilled water (saturated is approx one heaped tablespoon to a quart of water, easier with warm water)
10-20 drops of Lugols iodine
10-30 drops of tea tree oil, lavendula oil or a mix of these two, rosemary is also nice. I make stronger solutions to adults, weaker for children.
The Iodine turns clear in a few seconds so no problems with staining
Fill a squeezing bottle; massage the mix to your scalp, let it work for 15-20 minute, shampoo as usual. You only need about an oz a time, depending on how much hair.
Feels great and your hair will shine !