Vitamin D And Hair Loss

It is normal to lose around 100 hairs from your scalp each and every day. However, if the hair loss is more severe, there may be an underlying medical reason. Your body needs a number of key nutrients to function properly, one of which is vitamin D. If you have a vitamin D deficiency, there is now significant research to suggest you may also suffer from a variety of health conditions, one of which being excessive hair loss.

Vitamin D Deficiency Is Very Common

Vitamin D is formed naturally in the body through exposure to UVB rays from the sun. Your body then converts it into an active form and this is vital to your overall health. Research has shown that it helps to improve bone health (vitamin D deficiency causes rickets, a bone deformity, in children for instance), and also prevent diabetes, cardiovascular disease, and more. The Harvard Medical School has recently published a report to highlight to fact that vitamin D deficiency is once again prevalent, mainly because people no longer get enough sun exposure. This is because we all work long hours often cooped up in offices. This has led to an increase in rickets in children, and also in various other health conditions.

The Biology of Vitamin D

Vitamin D is often referred to as the ‘sunshine vitamin’. This is due to the fact that the body produces it naturally after sun exposure. The vitamin itself is more than a single element, however. It is actually a group of steroid-like, fat-soluble related compounds. There are, in fact, five different members in the vitamin D family, which are known as D1 through to D5. However, when we speak of vitamin D, we usually mean D2 and D3. Put together, these are known as ‘calciferol’.

Specifically, D2 (ergocalciferol) is synthesized from ergosterol. This is a substance that is not produced in the human body and must therefore be ingested. D3 (cholecalciferol) is synthesized in the skin after exposure to ultraviolet radiation, which absorbs 7-dehydrocholesterol (which is then converted to cholecalciferol). Once the human body has obtained vitamin D, it goes to the liver, which turns it into a prohormone called calcidiol. Calcidiol is converted to calcitriol, which is vitamin D’s active form and this happens in the kidney and by the immune system’s cells. It then binds to proteins so that it can be transported to the body’s organs.

Vitamin D is a hugely important compound. It helps the body in terms of cell differentiation and cell division. Furthermore, it strongly supports the immune system. Its main role is no less important, as it regulates levels of phosphate and calcium in the body. In fact, no matter how much milk people would drink, they would not be able to obtain any calcium from it if they did not have vitamin D.

Biologically speaking, vitamin D ensures calcium is properly balanced by making sure the intestines can absorb it properly. In so doing, the bones also re-absorb the mineral and this stimulates the parathyroid to keep serum levels of calcium regulated. This is a complex mechanism, but it does highlight just how important this vitamin is.

Understanding Hair Loss

Everybody loses hair on a daily basis. However, there are various illnesses that cause the incidence of hair loss to increase. These include thyroid problems, diabetes and lupus. These can all worsen existing hair loss, or accelerate it. Other factors can also contribute to hair loss. Things like a low protein diet, genetics, poor nutrition, stress and certain medication can all play a role. The most common cause of hair loss is hereditary, known as male (or female) pattern baldness (medical term ‘androgenetic alopecia). Around 80 million people suffer from pattern baldness in this country.

The Possible Link Between Vitamin D and Hair Loss

When people lose too much hair, or shed excessively, we speak of telogen effluvium. This means that between 100 and 200 hairs are lost each day, rather than the usual 50 to 100. According to various studies, vitamin D deficiency can be a major factor in telogen effluvium. Particularly, scientists have noted a correlation between serum levels of ferritin (a protein that allows cells to store iron) and vitamin D, specifically in 80 women who suffered from female pattern baldness. The conclusion was that both low vitamin D and low ferritin are linked to hair loss, which led them to conclude supplementation could benefit people who suffer from it.

Vitamin D Supplementation and Hair Loss

Scientists are still struggling to understand exactly why hair loss happens. Clinical research has shown, however, that there can be a link with vitamin D deficiency. At the same time, no exact cause and effect relationship has been determined. Yet, those who find it difficult to get out in the sun often or who, for whatever reason, cannot consume fortified foods like oily fish, cereal and dairy products, supplementation may be required. It is vital, however, to follow the instructions, because there is such a thing as too much vitamin D. In fact, at excessive levels, it can cause vomiting, nausea, constipation, poor appetite, abnormal heart rhythms, weakness, and mental confusion.

We know that low levels of vitamin D, known as hypovitaminosis, means the bones cannot mineralize properly. This means that all the minerals that are required for bone health, like calcium, are lost, leading to fragile, soft bones. When this happens in children, it is known as rickets. In adults, it is called osteomalacia.

However, other illnesses are now known to also be associated with hypovitaminosis. These include:

• Juvenile diabetes
• Rheumatoid arthritis
• Parkinson’s disease
• Multiple sclerosis
• Certain forms of cancer
• Alzheimer’s disease

Because vitamin D is such an interesting and vital vitamin, it is constantly being studied and new discoveries are made regularly. The last one indicated that vitamin D deficiency can cause the growth cycles of hair follicles to become inhibited.

Most people obtain their vitamin D through sun exposure. However, due to the risk of skin cancer, exposure is no longer advocated. Instead, scientists recommend people try to obtain their vitamin D through nutrition and supplementation. The issue with this, however, is that it becomes very difficult to calculate the recommended daily values. A range of factors (age, weight, ethnic origin) play a part in how much of the vitamin is needed and most people do get at least some sun exposure during the day.

The following table gives some guidelines on recommended daily values. However, scientists warn that this remains quite inconclusive because of the aforementioned factors. This is why it is important to speak to a physician in order to determine just how much vitamin D you can take. The table also highlights tolerable amounts, however, which is the maximum amount someone can take per day without experiencing negative side effects.

Life Stage Recommended Daily Dietary Allowance Maximum Tolerable Daily Intake
0 to 6 months 400 IU 1,000 IU
6 to 12 months 400 IU 1,500 IU
1 to 3 years 600 IU 2,500 IU
4 to 8 years 600 IU 3,000 IU
9 to 70 years 600 IU 4,000 IU
Pregnant or lactating women 600 IU 4,000 IU
Over the age of 70 800 IU 4,000 IU

Vitamin D as a Hair Loss Treatment

It is now no longer a secret that there is a link between vitamin D and the condition of your skin. It is also no secret, although few people realize this, that the health of the skin on your head (your scalp) plays a role on how it can stimulate hair growth and regrowth, and prevent hair loss. The link between vitamin D and hair loss, therefore is actually quite clear:

• Vitamin D can reduce the amount of hairs lost because it can provide essential nutrients to the hair follicle. Furthermore, it activates the hair shaft’s individual cells. The healthier a cell is, the healthier the shaft will be as well.
• It has been well-documented that the majority of people who suffer from excessive hair loss also have a vitamin D deficiency.
• Chemotherapy patients, who often lose all their hair, often see an improvement in their baldness when using a vitamin D topical cream. Their hair regrowth is generally quicker than that in people who do not use the cream. Their hair loss is also sometimes less significant.
• The quality of individual hairs is improved by taking vitamin D.

Vitamin D, Vitamin D Receptors and Hair Loss

Vitamin D receptors play a part in regulating the growth cycles of the hair follicles. Animal studies on mice have shown that hair loss always occurs in mice that have mutated vitamin D receptors. Similar studies were repeated on humans and showed the same results. If the receptors are inactive, then vitamin D itself cannot bind to them. The inevitable result is alopecia in that individual.

Unfortunately, in the mice trials, increasing levels of vitamin D through supplementation did not reverse the hair loss. It is believed that this is because they had mutated receptors, and these simply do not know what to do with vitamin D, even if it is available. This part of the study has not been replicated in humans yet. However, it is believed that if humans have a mutated vitamin D receptor, they may benefit from supplementation.

In a different study on mice, it was found that if vitamin D was supplemented, it would act on the keratinocytes. This, in turn, stimulated new hair growth. Scientists uncovered that the link is in keratinocytes, which were the compounds that caused the mutation in the receptor. This means that, if a mutation in receptors in humans is determined to be caused by keratinocytes, hair loss may be reversed.

Further studies are required to determine the exact link between hair loss and vitamin D. However, preliminary results, and particularly those with chemotherapy patients, are very positive. So long as people understand their daily recommended amount, it seems that vitamin D could play a very positive effect in reducing hair loss or even in restoring hair growth in some people.

Resources and References:

Is There a Link Between Vitamin D and Hair Loss? – Relationship between hair loss and vitamin D. (Vitamin D Council)
How I Treat Vitamin D Deficiency – Treatment of vitamin D deficiency. (