How long can hair regrow after Vitamin D-induced hair loss?

You’re absolutely on the right track — and your experience is very common for patients recovering from vitamin D deficiency–related hair shedding.

Here’s what’s happening:
When vitamin D levels are low (like your 13.2 ng/ml), the hair follicle cycle slows down — more hairs enter the telogen (resting) phase and fewer start growing.
Even after you correct the deficiency, it takes time for follicles to “reactivate.”

✅ What to expect:

Hair fall usually starts to decrease noticeably after 2–3 months,

New hair growth typically becomes visible after 4–6 months,

Full recovery can take up to 9–12 months depending on how long the deficiency existed.

Daily shedding of 20–30 hairs is actually within the normal range during recovery.
Your scalp is still rebalancing, and regrowth takes longer because the follicle cycle runs on a delay — meaning the new hair you’ll see next month actually started forming weeks ago.

Keep your vitamin D level above 40–50 ng/ml, maintain protein and ferritin intake, and consider PRP or topical minoxidil if you want to stimulate regrowth faster.

You’re improving — it just takes patience for the visible change to catch up with the biological repair process.

Dr. Arslan Musbeh
Hair Transplant Surgeon – Founder of Hairmedico
17+ years of experience in FUE, Sapphire FUE, and hair loss management

This answer has been approved by Dr. Arslan Musbeh. It is not a medical advice.

Hi there,

I can completely understand why you’re feeling worried, hair loss can be very stressful, especially when you’re doing everything right and hoping to see faster results. With vitamin D deficiency, the good news is that once your levels start improving, the excessive shedding usually slows down first (which you’ve already noticed), and then regrowth tends to follow.

Hair grows in cycles, and it can sometimes take 6–12 months before new growth becomes noticeable after correcting a deficiency. The daily hair fall you’re describing (20–30 strands) is actually within a normal range, so that’s a positive sign that your shedding has already improved.

For regrowth, patience really is key. The tiny new hairs often start as fine, short “baby hairs” that can be hard to see in the beginning. Continuing your vitamin D supplementation, supporting your body with a balanced diet, and avoiding harsh hair practices will give your hair the best environment to recover.

You’re on the right track, and while it can take several more months to really see the results, things are moving in the right direction.

Hi! Dr. Peterson here –
Vitamin D deficiency can definitely contribute to increased shedding and delayed regrowth, since healthy follicles rely on vitamin D signaling. The good news is that once levels are corrected, most people do see gradual improvement, but it’s important to set realistic expectations. Hair growth is slow and cyclical — it can take 6–12 months to notice visible regrowth, even after the trigger is removed.
A daily loss of 20–30 hairs is actually considered within the normal range, but if you’re not seeing new growth yet, it doesn’t necessarily mean the follicles are permanently damaged. Sometimes regrowth lags behind shedding by several months. Other contributing factors, like genetics, stress, iron or thyroid issues, can also play a role, so it’s worth making sure those have been checked as well.
Keep treating the deficiency and give it more time. Many patients don’t see “baby hairs” filling in until closer to the 6–9 month mark after starting treatment. If things don’t improve, a dermatologist can guide you on additional options like minoxidil, platelet-rich plasma (PRP), or other medical therapies to encourage regrowth.
Hang in there — improvement is likely, but patience is key.
All the best,Dr. Erik Peterson

It would be great if you can check the serum total vitamin D level again if it reaches 30 ng/ml. It takes at least 3-6 months after normal vitamin D level in order to see noticeable improvement.

So in a situation like this one needs to be careful. in fact, one needs to be very careful not to fall into a trap. Just because a patient’s vitamin D is found to be low that does not mean that is the cause of a person’s hair loss. in fact, a good portion of the time it is not and the low vitamin D is a red herring to the actual cause. I don’t know enough about your story to comment fully so be sure to review with an expert who knows all your story and who has a chance to see your scalp. Many people who think their low vitamin D is the problem are not correct. Even if your hair improves with vitamin D supplements it does not exclude an unrelated telogen effluvium that was transient in nature and set to resolve on its own anyways. Be sure to get expert advice if things don’t improve for you. The vitamin D hair loss trap is common and I see it every single day.