Vitamin D: why you and your skin need it

Daniel Judd BSc, MBiol

Are you feeling a bit achy and depressed? Is your skin suffering – slow to heal? It could be a lack of Vitamin D. Daniel Judd looks at why this vitamin is essential to our health and how to get it safely.

Vitamin D is an important molecule that’s responsible for a range of things in your body from keeping your bones strong to boosting your immune system. And when it comes to your skin it helps control skin cell growth and plays a role in wound healing, reducing inflammation, protecting against sun damage and maintaining that all important skin barrier function. It may even aid in weight loss, warding off depression and may even help you keep your hair.

But according to the NHS, one in five people in the UK may not be getting enough of this vital vitamin.


What is Vitamin D good for

The European Food Safety Authority allows vitamin D products to advertise a benefits to boosting normal immune, inflammatory and muscle function as well as reducing the risk of falling in people over 60. Vitamin D is being investigated as a possible drug to lower the risk of certain cancers but this is yet to be proven and products can’t be advertised as doing so.

One case where topical vitamin D is of real benefit is in treating psoriasis. This skin condition characterised by scaly, red and itchy skin is typically linked to the rapid overgrowing of skin cells. As vitamin D can control the rate at which skin cells grow it can be useful in combatting the over-growth seen in psoriasis.

Because of its role in the immune system it’s Vitamin D also plays a vital role in the ‘skin barrier’ – helping to keep skin healthy by regulating its ability to fight off invading bacteria. A study involving mice with a vitamin D deficiency were shown to have an impaired skin barrier and were more prone to skin infections.

But when it comes to eczema, skin pigmentation and vitiligo, the jury is still out, according to the Mayo Clinic in the US which says more research is required.

As one of the symptoms of a lack of vitamin D is hair loss, if you notice your hair is starting to fall out, taking a supplement could help. It won’t, however. help if there are other underlying reasons for your hair loss such as alopecia areata. It’s wise to check with your GP to discuss what could be causing the thinning.



How do we get vitamin D?

There are three main sources:

  1. The Sun: Vitamin D is known as the ‘sunshine vitamin.’ While exposure to the sun might get a bad rap, a little bit is important as your body converts cholesterol into vitamin D in your skin when its exposed to UV light. Around 5-30 minutes a day of exposure on the arms (without sunscreen) is usually enough for people to make enough Vitamin D depending on your skin colour. Paler people need less time while people with darker skin need closer to the upper time limit of 30 mins.
  2. Diet: Cod liver oil, fatty fish and egg yolks give you D3, the cholesterol your body converts into the Vitamin D it needs. Some foods like dairy products and vegetable oils are artificially fortified with extra vitamin D to increase our intake of it. Cooking food that contain vitamin won’t destroy it all – plenty should remain in the cooked product.
  3. Skincare products: A third route these days comes from skin care creams. There are a number of products coming onto the market that deliver Vitamin D via the skin – mimicking the sun’s delivery route. However, there is some debate as to how effective this will be and it will depend on the form of Vitamin D used in the products and how well the body breaks it down to its active form. That said, calcitriol (D3) has been used topically to treat psoriasis (see below).



Fatty fish like salmon and cod are good sources of Vitamin D


Why don’t we get enough Vitamin D?

Office jobs, less outside activities, pollution, and how far away you live from the equator can affect how much vitamin D you get. A greater awareness of the damage the sun’s rays can do means many people are spending less time in the great outdoors.

Other risk factors include:

  • The colour of your skin. People with darker skin are at greater risk of deficiency, particularly if they live further from the equator during winter and don’t eat enough foods rich in vitamin D.
  • Obesity has also been linked to vitamin D deficiency. Because Vitamin D is a fat soluable vitamin, it is stored in fat tissue and becomes less available for use.
  • Clothing that covers the whole body have also been linked to lower levels of vitamin D as the skin isn’t exposed to UV.


How do I know if I’m don’t have enough Vitamin D? 

Symptoms of vitamin D deficiency include:

  • bone related issues like rickets in children
  • osteoporosis in adults as not enough calcium is absorbed in the intestines, leading to weak and fragile bones.
  • muscle aches, weakness and twitching
  • depression
  • fatigue
  • hair loss (not associated with alopecia areata) and
  • wounds that are slow to heal.

Your doctor can confirm if you have a deficiency or deficit with a blood test.



Supplementary vitamin D is recommended by the British Association of Dermatologists for people at greater risk of UV induced skin cancer. This includes people with paler skin, a family history of skin cancer, people with more than 50 moles and people on immunosuppressive drugs.

The recommended IUs for vitamin D are:

  • children and teens: 600 IU
  • adults up to age 70: 600 IU
  • adults over age 70: 800 IU
  • pregnant or breastfeeding women: 600 IU

Vitamin D is stored in the body so it is important not to exceed the recommended daily intake unless advised by your doctor.


Can everyone take Vitamin D supplements?

There are a number of situations where increasing your vitamin D intake by supplementary or topical methods could be dangerous. Drugs including digoxin and thiazide diuretics should not be taken alongside high doses of vitamin D. Some thyroid, kidney, liver and hormonal diseases may also require consideration before taking vitamin D. Vitamin D should not be taken by anyone with high blood calcium levels. Some drugs like barbiturates and HIV drugs may interfere with vitamin D, giving a lower effective dose.

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