Daily Health

How Does Vitamin D Affect Hair Loss?

Did you know the human scalp contains approximately 100,000 hair follicles? That's a lot of hair — in theory. When those follicles don't behave as expected and you experience hair loss, it doesn't just affect how you look; it can significantly impact your sense of self and identity.

There are several causes of hair loss, such as hereditary hair loss, hormonal imbalance, mature hairline, and essential vitamins and mineral deficiencies. Regarding the latter, you may have seen a few claims about vitamin D helping with healthy hair growth. Although research is still growing, there is clinical evidence of a relationship between certain types of hair loss and low vitamin D levels.

So, is vitamin D beneficial if you are experiencing hair loss? Let's look at the connection between vitamin D and hair loss in more detail.

What is vitamin D, and what does it do in the body?

Vitamin D is one of the four fat-soluble vitamins. It naturally occurs in just a few foods like fatty fish, red meat, liver, egg yolks, and mushrooms. However, several foods are fortified with vitamin D, and it’s also available as a dietary supplement.

In foods and dietary supplements, it comes in two forms; vitamin D2 (ergocalciferol) and Vitamin D3 (cholecalciferol). D3 comes from animal-sourced foods, and D2 comes from plant-based and fortified foods. 

You actually get most of your vitamin D from the sun, as our body naturally produces vitamin D when exposed to sunlight. 

When you take in vitamin D from foods or the sun, it's useless to the body at first. It has to be transformed via the liver and kidneys into a usable form. Once your liver and kidney have done their jobs, the role of vitamin D is crucial to several biological processes, including:

  • Regulating serum levels of calcium and phosphate in the body — which helps to promote healthy bones and teeth
  • Reducing inflammation
  • Supporting the immune system
  • Increasing muscle strength
  • Promoting heart health
  • Regulating glucose

Vitamin D deficiency is also linked to certain types of hair loss — in particular alopecia areata. We'll delve into this in more detail below. 

The science behind vitamin D deficiency and hair loss

Alopecia areata is an autoimmune condition that results in the body attacking its own hair follicles. It leads to unpredictable hair loss on the scalp and the body. Several articles have linked alopecia areata to vitamin D deficiency.  

Data from one research study published in the British Journal of Dermatology in 2014 found that patients with alopecia areata had deficient vitamin D levels and that the deficiency correlated with disease severity. 

In the same year, another international journal found a significant link between alopecia areata and vitamin D deficiency. This study stated that vitamin D deficiency could be a significant risk factor for developing alopecia areata. 

More recent medical studies have also had similar results. A research paper published in 2018 stated that vitamin D deficiency was found in their patients with alopecia areata, and more so with increasing disease severity. 

It is thought that vitamin D plays a role in the hair follicle, particularly in the anagen phase of hair growth. This is the active growing phase where your hair grows to its entire length. When there isn't enough vitamin D in your system, it can prevent new hair growth. 

This has been seen in several historical studies on people with rickets. These patients have mutations in the vitamin D receptor gene that results in vitamin D resistance leading to sparse body hair, often causing total scalp and body alopecia. 

Data from another study found that serum ferritin and vitamin D levels were deficient in women with two other types of female hair loss; chronic telogen effluvium and female pattern hair loss.  

So, although there is not a large body of evidence regarding vitamin D deficiency to hair loss, there is a significant connection showing that vitamin D can play a role. However, vitamin D deficiency is not the only cause of hair loss. 

Other causes of hair loss

As mentioned at the beginning of this article, there are many common causes associated with hair loss:

  • Androgenetic alopecia: known hereditary hair loss or male/female pattern baldness. A 2017 study found a link between female pattern baldness and vitamin D deficiency. 
  • Age: hair growth naturally slows as you age.
  • Alopecia areata: an autoimmune condition.
  • Cancer treatment: such as chemotherapy or radiation treatments.
  • Hormonal imbalance: can be caused by several reasons, such as polycystic ovary syndrome or starting/stopping birth control.
  • Telogen effluvium: temporary hair loss that can occur after stress, shock, or a traumatic event. Although not considered the leading cause, vitamin D deficiency has been linked to telogen effluvium.
  • Medication: there is a wide range of drugs that can contribute to hair loss, like certain acne medications, antibiotics, immunosuppressants, and more.
  • Pregnancy/childbirth: often due to hormonal imbalance or stress levels.
  • Certain illnesses: such as thyroid disease, skin infections, and conditions like psoriasis.
  • Types of hair care and styles: using tight hairstyles or harsh chemicals on your hair.
  • Essential vitamins and mineral deficiencies: such as vitamin D, iron, protein, and zinc. 

As there are so many factors to consider, you should speak to your healthcare practitioner if you are worried about your hair loss. Since vitamin D has been linked to several hair loss causes, they might want to explore if you are deficient in vitamin D.

Symptoms and causes of vitamin D deficiency

Vitamin D deficiency is actually very common. Recent study data suggests that 37% of the Canadian population are vitamin D deficient, and 7.4% are severely deficient. 

If you're wondering if you have low levels of vitamin D, then hair loss is not the only symptom. Symptoms can differ between children and adults, but common symptoms of vitamin D deficiency in adults include:

  • General tiredness and fatigue
  • Muscle weakness
  • Muscle pains and cramps
  • Bone pain

Although we get a lot of our vitamin D from sun exposure, too much sun exposure can lead to concerns like skin ageing and skin cancer. Therefore many people often aim to get their vitamin D from their diet or vitamin D supplements.

If you spend a lot of time indoors, get little sun exposure, or live in an area with little natural sunlight, you might be at a higher risk of developing vitamin D deficiency. Other people at higher risk of being vitamin D deficient include:

  • People who have a milk allergy or lactose intolerance 
  • People who consume an ovo-vegetarian (which excludes all animal products except eggs) or vegan diet 
  • Older adults (you're less able to make vitamin D from sunlight as you age)
  • Infants who are breastfed (vitamin D supplements are recommended to breastfed babies, as not enough vitamin D is found in breast milk)
  • People with dark skin (darker skin makes less vitamin D from sunlight exposure)
  • People with certain conditions, such as liver diseases, Crohn's disease, celiac disease, or ulcerative colitis 
  • People who are obese
  • People who have had gastric bypass surgery

How do you know if you have low vitamin D levels?

If you are worried that your vitamin D levels are low, especially if you are experiencing symptoms like hair loss, then speak to your healthcare practitioner. They can arrange a blood test that measures the amount of serum vitamin D in your blood. 

If your healthcare practitioner finds that your vitamin D levels are low, then they will likely recommend several treatment options:

  • Including more foods in your diet that are higher in vitamin D, such as trout, salmon, tuna or mackerel, egg yolks, mushrooms, beef liver, or foods that have been fortified with vitamin D like certain milk, dairy products, or breakfast cereals. 
  • Spending more time in the sunlight. But, too much sun exposure is associated with skin cancer, so it's important not to spend too much time in the sun and always wear sunscreen. 
  • Adding vitamin D supplements to your diet. In Canada, the recommended dietary allowance for vitamin D is 600 IU per day for adults 19 years and older — increasing to 800 IU daily when you reach the age of 71. 

If you begin to take vitamin D supplements, then follow the medical advice and written instructions from your healthcare practitioner. Too much vitamin D can be harmful, causing toxicity, and excessive levels of vitamin D are usually caused by taking too much vitamin D from dietary supplements. Your body limits how much vitamin D you make from the sun, so too much sun will never cause vitamin D toxicity. 

Vitamin D toxicity can cause nausea, vomiting, muscle weakness, confusion, pain, loss of appetite, dehydration, kidney stones, and in extreme cases, kidney failure, irregular heartbeat, and even death. 

Treating and preventing hair loss

Hair loss affects everyone differently, and you might be completely comfortable with it. In which case, you don't need to do anything but embrace it. 

If you are experiencing hair loss, thinning, or shedding, and it does worry you, then vitamin D deficiency could be one of the contributing factors. It's worth getting your vitamin D levels checked out. 

But, there are also other medical treatment options available that can help you slow down, stop hair loss, and sometimes regrow hair. A prescription for hair loss medication might be the right option for you — and Felix can help you with that. 

Why not start with our online consultation to see if you qualify for Health Canada authorized hair loss treatment? Our licensed healthcare practitioners can help you find out if hair loss medication is the right fit for you and arrange for it to be delivered right to your door. You don't have to accept hair loss. You have options. Explore them with Felix

WRITTEN BY
Felix Team
Updated on:
August 30, 2021
Medically reviewed by
Dr. Sarah Lasuta
Family Physician, MD, CCFP
Disclaimer

The views expressed here are those of the author and, as with the rest of the content on Active Ingredients, are not a substitute for professional medical advice, diagnosis, or treatment. If you have any medical questions or concerns, please talk to your healthcare provider.

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