Insulin resistance, metabolic syndrome, and hair loss are all associated with one another because of each condition (or symptom) is related to chronic, systemic inflammation. Addressing your vitamin D deficiency may help, but if you’re supplementing with that much vitamin D, you should also supplement with vitamin K2, A, and any other vitamin D adjunct. See if your levels rise over the next few weeks, and then retest. If they’re still low, that would suggest something else is going on — potentially hyperparathyroidism (in which case you should test PTH and TSH alongside retesting calcium and vitamin D).
It appears that vitamin B6 in its P-5-P form (also called PLP) may affect the function of specific receptors in cells, whose job is to bind to and activate various hormones, including testosterone. A number of studies found that increased PLP concentrations can reduce the activity of these receptors, thus making cells less responsive to hormones. Meanwhile, the reverse effect was found when intracellular PLP concentrations were decreased. While this effect may be useful for several sex hormone-related conditions, it is currently unclear whether this mechanism can have any benefit for boosting testosterone levels. 4 5 6