My first thought is that you may not be getting enough protein.

to quote from a typical cite on the topic "Hair loss may occasionally
be caused by lack of protein in the diet. Some people who go on crash
diets that exclude protein or who have abnormal eating habits may
develop protein malnutrition. When this happens, the body will help
save protein by shifting growing hairs into the resting phase.
Increased hair shedding can occur 2 to 3 months later."

Mary G

There are many reasons for hair loss. Some include low thyroid
function, diet deficiencies, aging in men etc. The first two could be
a consequence of your dieting. So, it is pertinent just how you are
dieting and what you are eating, what's your weight and height etc.

Also, if you can, take pictures of your bald spot to compate what
happens over time.

I have read anecdotes that suggest all diets produce some hair loss.  I
subjectively see some loss or thinning in the front of my hair.  When I
brush it, I see a lot of hairs fall out too.  This area is where my family
develops male pattern baldness.  I have wondered if my diet may have
improved my testosterone.

As to your question.  I don't really know, but my guess is that hairloss
around an existing bald spot would be a continuation of male pattern
baldness.  I think losses from male pattern baldness may be permanent.  If
you were a woman with a generalized mild hairloss, I would expect it to grow
back.