Vitamin D Deficiency, Benefits, Types & Sources

Vitamin D is the sunshine vitamin. The benefits of vitamin D include healthy bones, teeth, muscles and a properly functioning immune system. Sources include sunlight, food and supplements. Signs of Vitamin D deficiency include bone pain, muscle weakness, fatigue and a depressed mood.

Vitamin D sunshine

What is Vitamin D?

Vitamin D is a fat-soluble vitamin that is essential for good health and has been associated with many health benefits. It helps the body function properly to stay healthy.

Types of Vitamin D

There are two major types of vitamin D. These are vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol).

The human body does not produce vitamin D2. It comes from plants such as mushrooms.

We can produce vitamin D3 in the skin when exposed to sufficient sunlight.

Conventional Vitamin D3 is obtained from animal-origins including lanolin (sheep wool grease) or animal skins. It is also now available from plant sources, so it is suitable for vegetarians and vegans.

What are the Benefits of Vitamin D?

Why we need vitamin D is that is vital for good health. A key benefit of vitamin D include is that it supports a properly functioning immune system to fight infections. Other benefits of vitamin D include the nutrients within it playing a key role in developing and maintaining healthy bones, teeth and muscles.

Research has linked vitamin D to reducing the risk of some cancers.

It helps fight infection, which is recommended as a tool in combating coronavirus. Recent studies provide evidence that vitamin D can help reduce the severity of Covid-19, providing there are adequate levels of vitamin D in the body.

Furthermore, a number of studies also suggest it helps support a healthy heart, lungs and brain.

How Much Do I Need? 

It is recommended that the average person needs 10 µg of vitamin D each day.

Vitamin D Deficiency

Vitamin D deficiency is not having enough vitamin D in your body. Symptoms of deficiency can include bone pain, muscle weakness, fatigue and a depressed mood.

Among the more severe results of vitamin D deficiency are rickets in children as well as osteomalacia in adults. Both are characterised by loss of mineral from the bones and result in skeletal deformities such as bowed legs, retarded growth and inadequate mineralisation of tooth enamel and dentin. The link between vitamin D deficiency and the onset of osteoporosis in the elderly has been widely studied.

Who is at Risk of Vitamin D Deficiency?

You may be at risk of having a deficiency if you:

  • Do not get enough sunshine by avoiding the sun or covering up from sunlight.
  • Have darker skin.
  • Are older or have a condition which means you do not get outdoors enough.
  • Are a pregnant woman.
  • Are a baby.
  • Have a vitamin D metabolism health condition.
  • Are a vegetarian or vegan.

How Do We Get Vitamin D?

We get it from these sources:

  1. Exposure to sunlight.
  2. Food.
  3. Supplements.


Vitamin D is called the sunshine vitamin. This is because we get it from the sun. When the sunlight’s ultraviolet (UV) rays touch our skin, our bodies convert this into vitamin D3. The amount of vitamin D we produce is impacted by the season of the year, an individual’s skin colour, age as well as how much of our skin is exposed to sunlight. Higher levels of vitamin d are generally available from sunlight outdoors during Summer and Spring in Ireland. Due to the risk of skin cancer from harmful UV rays, it is important that people do not overexpose to sun or get sunburnt.

During the Autumn and Winter months, people in Ireland generally do not get enough sunlight. Therefore, a vitamin D supplement can help.


Vitamin D can also be accessed via certain food that are rich in the vitamin and from eating a balanced healthy diet. Food that can be good sources include:

  • Oily fish such as mackerel, tuna, salmon, herring and sardines
  • Red meat.
  • Liver.
  • Fortified foods such as breakfast cereals.
  • Dairy products such as cheese and egg yolks.
  • Orange juice.
  • Soy milk.
  • Cod liver oil.


Dietary supplements are another source. Beeline Healthcare offer a full range of vitamin D supplements for adults, babies, toddlers and teenagers. This helps combat vitamin D deficiency.

The Health Service Executive (HSE) recommend vitamin D supplements for all babies 0 to 12 months old. The Food Safety Authority of Ireland (FSAI) recommend during the extended Winter months from Halloween to St Patrick’s day, that all children aged 1 to 5 years old need to be given a low-dose (5 μg) vitamin D-only supplement. This will help make up for the lack of skin synthesis of vitamin D from sunlight during this season. The NHS recommend a daily supplement for children aged 1 to 4 years old of 10 micrograms of vitamin D.


Vitamin D plays a key role in a healthy life fighting infection and disease, while reducing depression. It is vital for healthy and immune system, bones, teeth and muscles.

Sunlight along with a balanced healthy diet and supplements combine to combat vitamin D deficiency for all ages.

Questions Vitamin D

  • What is vitamin D deficiency?

    Vitamin D deficiency is the body having inadequate levels of vitamin D. Low levels of vitamin D can compromise our immune response as well as causing symptoms including bone pain, muscle weakness, fatigue, a depressed mood and rickets in children.

  • What are the symptoms of low vitamin D?

    The symptoms of low vitamin D levels include a compromised immune response, bone pain, muscle weakness, fatigue, a depressed mood and rickets in children.

  • How much vitamin D should you take?

    It is recommended that the average adult needs 10 µg of vitamin D each day.

  • What foods are high in vitamin D?

    Foods that are high in the vitamin D include fatty oily fish such as mackerel, tuna, salmon, herring and sardines, red meat, liver, fortified foods such as breakfast cereals, dairy products such as cheese and egg yolks, orange juice, soy milk and cod liver oil.

  • What are the types of vitamin D?

    There are two major types of vitamin D. These are vitamin D2 ergocalciferol, and vitamin D3 cholecalciferol. Vitamin D2 is not produced by the human body. Sources include plants such as mushrooms. Vitamin D3 is produced naturally in the skin, when exposed to sufficient sunlight. Other source include supplements and certain foods such as oily fish.