Vitamin D – the Sunshine Hormone for Viral Infections

Vitamin D – the Sunshine Hormone for Viral Infections

Vitamin D – the Sunshine Hormone for Viral Infections

Vitamin D – the Sunshine Hormone for Viral Infections









Think Sunshine, think Vitamin D (Vit D) production in your body.

Vit D is not only a vitamin; it is also a pro-hormone which is absolutely valuable nutrient for your body as it is involved in so many functions in the body. That means that Vit D is essential to the body.

Vit D deficiency has been linked to increased risk for many common and serious diseases, including some common cancers, diabetes, cardiovascular disease and osteoporosis. Studies suggest that exposure to sunlight which enhances the production of vitamin D in the skin, prevents many chronic diseases. Vitamin D is essential for the formation of growth and health of bones. Additionally, it is necessary for normal calcium absorption and immune function. It also improves muscle strength and helps reduce inflammation.

What are the Actions of Vit D?

Vit D’s claim to fame has always been it’s vital role of bone homoeostasis. Vit D regulates calcium absorption and support bone density, promote bone mineralisation and prevent severity of osteoporosis.

Function of Vit D:

  • Supports and promotes immune defence
  • Regulates heart muscle function
  • Regulates cell cycles
  • Supports Insulin secretion
  • Involved in Thyroid hormone secretion

Effects of vitamin D deficiency

Vitamin D deficiency can have serious short and long-term effects on your physical and mental health.  Measure and address Vit D deficiency if you have some of these symtoms.

Physical – Prolonged vitamin D deficiency can adversely affect your bone density, cause brittle bones, otseopenia and osteoporosis, impaired repair and healing capacity of the body and rickets in children.

Mental – Vitamin D deficiency can lead to depression and anxiety. Some may experience stress, feeling of overwhelm, fatigue, insomnia and loss of sexual interest.

Protection against Respiratory Viruses

There is a lot of concern about protecting the body against infections especially in people with respiratory and lung diseases such as influenza and Coronavirus.

Although Vit D does not treat Covid-19 or viral infections, pro-active measures need to be taken to boost the immune system and cellular health to protect against serious illnesses.

How does Vit D Protect the Immune System?

Deficiency of Vit D can increase the risk of infection by viruses or other pathogens.
Vit D helps protect the immune system by a number of mechanisms:

  • Decreases inflammatory cytokines
  • Protects the lung and gut cellular membranes and microbiomes
  • Reduces the detrimental effects of allergic reactions
  • Support mitochondrial function required for energy and ATP production

The Value of Vitamin D

The active form of Vit D, 1-25-hydroxy-Vit D binds to a gene receptor called Vit D receptor (VDR) to form a complex which helps develop an innate immune response and hence induce immunity against infections.

Note that VDR’s are found in many cell organelles like T-cells, neutrophils, macrophages and dendritic antigen-presenting cells which form part of the body’s defence mechanism.

The immune defence cells like macrophages are responsible for converting the inactive form of Vit D 25-hydroxyvitamin D (D2 or D3) into active 1,25-OH-Vit D. Vit D is usually regulated by Calcium levels in the liver and kidney for it’s Vit D manufacturing pathway.

Vit D is required for cellular microbial health of the mucosal surfaces of the gastrointestinal tract and respiratory tract. Vit D supports microbial balance in these membranes to promote immune tolerance and reduce inflammation.

Studies have shown that Vit D Deficiency has been associated with pathogenic bacterial infections in the gut. (1)
Vitamin D deficiency in the lung is also associated with increased levels of pathogenic anaerobic bacteria which leads to inflammation in the lungs.(2)

How does Vit D support Energy Production in the Mitochondria?

VDR’s are found in the mitochondria in each cell of the body. Mitochondria are energy organelles in each cell which regulate immune responses. When Vit D is deficient, VDR signalling in mitochondria is reduced which leads to increased mitochondrial respiration, oxidative stress, and cell death. Vit D Deficiency stimulates oxidative damage by enhancing reactive oxygen species (ROS) effect on the cell signalling. The oxidative damage and stress may be further exacerbated by nutrient deficiencies, or toxic exposures.

Oxidative stress is often induced by viral pathogens to increase viral replication within cells.

How to Test for Vit D?

Vit D in the form of  25-OH Vitamin D (Body’s Reserve) and 1,25-OH Vitamin D (Active Form) can be measured in both a blood draw or a blood spot (DIY finger prick) sample
Ideally, measure both forms of Vit D, both inactive and active.

See Testing for vitamins video to ascertain which test is right for you.

Evaluation of mitochondrial function – how the body utilises fats, carbs and protein in food to produce energy in the form of ATP with Organic Acids. Organic acids reveal metabolic blocks in mitochondrial ATP production such as dysbiosis, B-group vitamin sufficiency and immune function.

Organic acids provide guidance for nutritional supplementation and of course, microbial and immune function.

By evaluating Vit D and organic acids and supplementing appropiately, multiple health outcomes can be improved and the risk of infections from the flu or other viruses ca be reduced.

How do you get more Vitamin D?

In Australia, excessive sun exposure  has also been proven to significantly increase our risk of skin cancer. Finding the right balance of exposing our skin to sunshine to derive the adequate vitamin D can be challenging.

How much you need may depend upon your personal circumstances, but recommendations from the National Health and Medical Research Council¹ include:

5 micrograms (200 IU) for children, adolescents and adults aged 19–50 years
10 micrograms (400 IU) for adults aged 51–70 years
15 micrograms (600 IU) for adults over 70 years of age

Compounding pharmacists make up much higher doses of Vitamin D which can be orally administered daily, weekly or monthly, Injectible Vit D is available from your doctor if severley deficient.

Vit D is best taken with its cofactors like Vitamin K, Calcium, Boron and Magnesium.

Vitamin D in Foods

Increase your Vit D levels bi increasing foods rich in Vitamin D:

Fish – cold water fatty fresh fish not only contain a good amount of vitamin D per serving, but they also provide the body with omega-3 fatty acids. Herring contains the most vitamin D, but others including salmon, catfish, sardines, mackerel, and bluefish.

Cod liver Oil – One tablespoon of this nasty tasting oil which I remember talking as Cod liver oil and Malt is nutrient-packed with Vit A and Vit D providing adequate Vit D daily allowance.

Eel – A 3.5-ounce serving of eel has around 900 IU of vitamin D and provides more than 150% of the daily recommended intake of vitamin D. The snake-like fish also supplies hefty doses of vitamins A and B12 that support immune function and energy production.

Eggs – One large egg contains about 40 IU of vitamin D, a powerhouse for riboflavin, vitamin B12, phosphorus, and selenium

Milk – most pasteurized cow’s milk is fortified with vitamin D.

Liver – beef or chicken liver contains about twelve percent of daily vitamin D.  Even though it is a source of vitamin D, liver is also high in cholesterol.

Mushrooms – Mushrooms contain ergosterol, a “pro-vitamin” that is converted into vitamin D by exposure to sunlight.

Caviar and fish roe – Approximately 1 tablespoonful of caviar gives about 33 IU of vitamin D. It is also an excellent source of vitamin B12, iron, magnesium, and selenium.

Fortified orange juice, yoghurt, cereal, tofu- some brands of foods are fortified with Vitamin D


  2. Shukla SD, Budden KF, Neal R, Hansbro PM. Microbiome effects on immunity, health and disease in the lung. Clin Transl Immunology. 2017;6(3):e133.