Why do our bodies need Vitamin D and how do I know if I am deficient?

 Vitamin D is one of the most common deficiencies. It is estimated that 1 billion people globally have Vitamin D deficiency and 50% of the global population have Vitamin D insufficiency. It is estimated that about 90% of our Vitamin D comes from exposure to sunlight whilst a small proportion comes from our diet. Individuals with darker skin have increased amounts of melanin in their skin which decreases the efficacy of Vitamin D absorption which is why people with darker skin are at greater risk, particularly in the UK where from October to March, the rays from the sun are not strong enough to enable our bodies to make vitamin D. This is one of the reasons that the Department of Health and the NHS now recommend that everyone in the UK should consider taking a vitamin D supplement from October to March. The elderly, overweight and those living in the Northern Hemisphere are also at greater risk. A 2017 study additionally revealed that shift workers, health care workers and indoor workers are at increased risk of developing a deficiency due to reduced outdoor time and sunlight exposure.  Apart from this, malabsorption syndromes such as celiac disease, short bowel syndrome, gastric bypass and cystic fibrosis may also lead to Vitamin D deficiency. Medications such as phenobarbital, carbamazepine, dexamethasone, nifedipine, spironolactone, clotrimazole, and rifampin induce hepatic p450 enzymes which speed up the degradation of vitamin D.

Why do we need Vitamin D? 

Vitamin D's primary and vital function in the body is to maintain blood levels of calcium. It does this through increasing the amount of calcium absorbed from food in the small intestine. This helps the body to form and maintain healthy bones. A deficiency in vitamin D can lead to osteomalacia or rickets. A deficiency of vitamin D also increases the risk of developing osteoporosis and experiencing fractures and broken bones. Apart from this, vitamin D deficiency has also been associated with increased risks of cancer development, particularly breast, colon and prostate cancers. Researchers have found that increased sunlight exposure and circulating vitamin D are associated with reduced occurrence and mortality in many types of cancer. Vitamin D is well known for its impact on the immune system and studies suggest that inflammation is often at the root of many modern autoimmune diseases including multiple sclerosis, rheumatoid arthritis, digestive disorders and high blood pressure. University of Aberdeen researchers studied patients in the North of Scotland which has the highest rate of MS in the UK who were treated during the winter with UV-B light therapy. Dr Anthony Ormerod, Clinical Reader in Dermatology at the University, said: “Our study shows that UV-B light, which mimics sunshine, can have a striking effect on the immune system of patients." 
In addition, a study in 2018  from Trinity College Dublin linked vitamin D deficiency with an increased risk of depression of over 75%  over a four year follow up period. 

What are the symptoms of Vitamin D deficiency? 

There is evidence to suggest that people with vitamin D deficiency are at increased risk of developing health conditions such as osteoporosis, autoimmune conditions, depression and cancer. Symptoms can also include weakness, chronic fatigue, depression, insomnia, anxiety, weakened immune system, inflammation and weak or broken bones. We would recommend that you are tested for vitamin D deficiency if you experience any of these symptoms. Vitamin D tests are available on the NHS and in our Nourishing Insights clinic.  This is a simple pin prick blood test which can be done at home. Find out more about Vitamin D testing and order here. 

How can I optimise my vitamin D levels? 

The main way in which we obtain vitamin D is from exposure to natural sunlight from the sun. When UVB rays land on the skin, a substance in the skin, 7-dehydrocholestrol is converted into vitamin D3. There are two types of supplemental vitamin D; Vitamin D2 and Vitamin D3. The type of vitamin D our bodies makes naturally is vitamin D3. Whilst the body is able to convert some D2 for use, vitamin D3 is believed to convert 500 times faster than D2 and is estimated to be four times more effective in humans. Most experts suggest spending 20 minutes in the sun without suncream (suncream blocks the absorption of vitamin D) to enable your body to absorb vitamin D naturally without damaging the skin. For darker skinned people, the time recommended increases to around 40 minutes. If you do not want to expose your skin to the sun, you should use a good quality supplement to make sure you are obtaining enough vitamin D to protect your immune system, bones, joints and general health. 

Are there any food sources? 

Sunlight is the best source of vitamin D and it is difficult to obtain vitamin D only from food. However, there are some food sources and research suggests that eating foods which are rich in Vitamin D can help you acquire more. Some of the best sources of vitamin D in foods are halibut, mackerel, salmon, herring, trout and eggs. Mushrooms are one of the only plant sources of vitamin D and they acquire vitamin D the same way the human skin does, through exposure to the sun. The vitamin D content of mushrooms is increased through exposure to Ultra Violet light. The quantity of vitamin D in mushrooms can vary dependant on how they are grown. 

Who should supplement and how much should I take? 

Current Department of Health recommendations suggest the following ‘at risk’ groups should be using a vitamin D supplement all year round. These include:

• Infants and children under 5 years of age
• Pregnant and breastfeeding mothers
• People over the age of 65
• People who have little or no exposure to the sun
• People with darker skin pigmentation

From October to March the Department for Health recommends that everyone should supplement with Vitamin D. However, bare in mind that many of us now are spending little time in the sun and when we are we are wearing sun creams or covering up. Even in hot countries where people are going from air conditioned homes to offices and malls with little exposure to sunshine has led to a global epidemic with deficiency. For example, in countries such as Pakistan it is estimated that 80% of the population is deficient. In addition, it is estimated that vitamin D has a half life of about 15 days which would mean that every 2 weeks our levels halve without ongoing exposure to sunshine or supplementation. Therefore, your holiday in the sun in February is not going to help you in April. 

Dosages vary according to age, bodyweight and level of deficiency. Testing is recommended to optimise your dose. 

Are there other nutrient considerations when supplementing with Vitamin D? 

Vitamin D and K2 

Vitamin D and Vitamin K2 work synergistically with each other to ensure that calcium is directed out of the arteries and into the bones where it helps improve bone density.
Without enough vitamin K2 calcification within the arteries can occur. We normally advise a combination product of D and K2 for the post-menopausal age group. 

Vitamin D and Magnesium 

Magnesium plays a key role in determining how much vitamin D our bodies can make. It’s suggested that people whose magnesium intake is high are less likely to have a vitamin D insufficiency than people whose magnesium levels are low.
It’s also claimed that magnesium supplementation increases vitamin D levels in people who are deficient in the vitamin, but causes a reduction in people whose intake is high. Too much vitamin D can increase calcium levels, which in turn can lead to certain health complications.

To learn more about magnesium and signs of deficiency, have a look at our blog. 

To find out more about Vitamin D supplementation contact us here, or come and visit us at 44 St Andrew Street Aberdeen. Nutritional Therapy consultations are also available on Zoom and skype.  More information here.