Hi, all.
It's kind of interesting to me to hear that the methylation status may be affecting the presence or absence of lunulas. I don't understand why for sure, but that has never stopped me from offering a hypothesis in the past!

-) So here's one:
It's known that the nails are composed of proteins called keratins. The mechanical strength of the nails (and the hair, which is made from the same class of proteins) is due to crosslinking between the protein molecules by formation of cystine disulfide bonds between adjacent cysteine residues. When there is a methylation problem, it tends to affect the availability of cysteine, about half of which is usually made from methionine by the combination of the methylation cycle and the transsulfuration pathway. I suspect that when there is a deficiency of cysteine, the nails and hair are made of the types of keratin that don't contain as much cysteine as are usually used. The result is likely to be weaker nails and hair.
The lunulas are the visible part of the nail matrix, which is where the new nail material is being produced. O.K., here comes the hypothesis: Maybe a shortage of cysteine slows the production of new nail material and shrinks the nail matrix, so that it retreats back underneath the cuticle.
It is known that people who have kidney disease and have to be on dialysis tend to have fewer lunulas. Several studies have shown this. It is also known that the kidneys are normally one of the organ types that are able to convert methionine to cysteine, by virtue of the fact that the kidneys have a fully functioning transsulfuration pathway (as do the liver, the pancreas, the intestine, the lens of the eye, and to a much lesser extent, the brain). So I think that this fact might be consistent with the hypothesis offered above.
I would be interested to know if others who try the methylation-type treatments (Freddd's or the one I have suggested or some variation of these or the others out there now) also experience appearance of lunulas where they were absent before.
Best regards,
Rich