I've been dealing with thinning hair from thyroid issues for over a decade, so be sure and have that checked out. It did get worse with lyme.
The b vitamins are supposed to help, but really everything you do to boost your immune system, which you should be doing for treating lyme, would help too.
MTHTR single mutation; Positive Igenix IgG Jan 2017; March/Apr '17: doxy, Tinizadole. 5/1 samento and mino/tini. 5/28- back to doxy, added activated charcoal. 6/9 - stopped antibiox; staying with samento, red root and houttiya and supps. tried LDN; 8/24 rifampin, samento, red root and supps. On and off rifampin. 1/1/18 - 1/20 rifampin. Herbs and vitamins only now.