D.B.
I had a lot of hair loss as a side effect of either low thyroid or the meds for it. Not sure which. I know that's not the cause of your problem, but I've known others who have had hair loss from a whole host of other things, including hormonal changes associated with aging (ugh, I know - you're only in your 40s). We tend to think of men as the ones who lose hair but women are affected as well. The fact that yours isn't growing so rapidly is kind of a tip-off too. I reversed my hair loss with comprehensive supplementation - that seems to be the key for a whole host of health issues. Based on the scientific seminars I've attended, I'm convinced that overall depleted soils and nutrient-deficient soils are the cause of the rise in preventable diseases. Cellular nutrition is the key - and you can't get it from pills or pre-mixed liquids or those junk protein shakes they sell at the gym. I chose, based on extensive study, a patented (proven safe, effective, unique) formula which took care of my hair loss, my breast cysts and my allergies, and I haven't had bronchitis or any illnesses in years. No one in my family has even had a sick visit in 5 years.
I also think the new research on epigenetics is going to be the breakthrough of the decade - our genes are made less efficient by the onslaught of poor nutrition (not just the processed foods and additives, but the poor nutrient levels in the fresh food we buy), environmental toxins, and aging. So the latest research on genes been helped back to their basic function without the damage caused by our lifestyles and genetically modified foods is the most exciting. There is a supplement now available to help with that too, and the major clinical studies by multiple research institutions (not those studies funded by the drug companies!) is extremely promising. I've seen additional results with that as well.
Based on my studies, I'd say the prenatal and biotin aren't doing as much as you would want.