Brief Answer:
Possibility of androgenetic alopecia with/without Chronic telogen effluvium

Detailed Answer:
Hello. Thank you for writing to us.

I have gone through your query and I understand that you are concerned about thinning and increased hair shedding.

Though dandruff is a common cause of increased hair shedding but it is usually not associated with thinning of hair/ reduced hair volume.

Thinning i.e reduced hair diameter and hair volume is more of a feature of androgenetic alopecia (AA) wherein patients notice a gradual decrease in hair volume/ density and increased hair shedding mainly from the center part of scalp i.e front, mid and vertex part of scalp. Patients may also complain that there hair does'nt grow as long as it once used to and falls prematurely.

In addition to dandruff and androgenetic alopecia there might be other contributing factors to increased hair shedding like dietary, metabolic, preceding illness, weight loss, seasonal etc. Amongst dietary factors reduced Iron stores is directly responsible for increased hair sheddng.
These factors induce transition of hair from growth phase (anagen) to resting phase (telogen) and it is subsequently shed (Telogen Effuvium).
Hair loss due to one or more of these factors is reversible on correction of underlying factor(s) e.g replacement of iron stores in those who have below normal serum ferritin levels.
There is an entity known as Chronic telogen effluvium (CTE) in which hair growth cycle appears to be reset so that the growth phase Or anagen period of hair is shortened however in CTE hair thinning is not a primary complain i.e hair is thick and moderately long.
Though you have longer hair but that does not necessarily put a strain on roots and is not a cause for increased hair shedding.

I would suggest a few lab test like thyroid levels i.e TSH levels and serum ferritin levels as an indicator of iron stores etc.

If I was the treating doctor I would start you on an Oral Iron supplement if ferritin levels are below normal. I would also start you on an Oral Biotin supplement. Biotin supports and promotes hair growth. I can see that you took Vitamin B 7 supplement for just a month. They can be restarted and continued longer i.e 6 months.
Topically I would suggest you to use a Minoxidil 2% solution, twice daily, at scalp skin. Minoxidil is also a hair growth promoter and accelerates hair growth.
These are prescription medications and should be taken under supervision and guidance of a dermatologist. I suggest that you visit a dermatologist in your region for a confirmatory diagnosis and for the needful.
An Innovative therapy for hair fall is Platelet rich plasma therapy (PRP) wherein patients own platelet rich plasma prepared by centrifuging whole blood is injected into scalp skin. Mechanism of action being growth factor that are released on platelet activation. These growth factors stimulate hair growth. Almost all types of hair fall responds to PRP and it is rapidly gaing importance.
You may continue with antidandruff shampoo, thrice or more in a week.

Regards

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