D2 also called Ergocalciferol is the plant based source of vitamin D
D3 or Cholecalciferol is the animal based source of vitamin D
The best source of Vitamin D is the sun. Once the UV radiation reaches us, our skin transform it into Cholecalciferol D3. It is recommended to get a minimum of 10min a day of sun exposure. In winter the sun is not strong enough to provide us with enough Vitamin D, but in summer it is, even through our clothes.
Sources of Vitamin D
The richest dietary sources of Vitamin D are oily fish such as sardines, mackerel, salmon or herrings. Beef liver, eggs and butter contain Vitamin D but in modest quantities.
Mushrooms also contain vitamin D but in much smaller quantities.
Cow’s Milk, orange juice, soy milk and breakfast cereals can be sources of Vitamin D as they are fortified in some countries. Cow’s milk isn’t fortified in the UK, but many plants based milks such as Oatly are.
Non active form to active form
In order for the body to be able to use vitamin D for important metabolic functions,both D2 and D3 forms have first to be converted into the active form. The conversion process is the same for both. Vitamins D2 and D3 are first converted into Calcidiol via the liver and then into Calcitriol via the kidneys. Calcitriol is the active form of Vitamin D our body can use for metabolic functions.
Let’s have a look at Vitamin D main functions
Calcium/Bone Health: Vitamin D controls the equilibrium of Calcium in our body. It also increases intestinal absorption of Calcium and Phosphorus. A vitamin D insufficiency can therefore impact bone health and cause pathologies such as osteoporosis, rickets, osteomalacia.
Immune Health. Vitamin D plays a key role in our immune health by decreasing inflammatory response to viral infections, and possibly increasing our elemental immunity. Vitamin D may also prohibit the development of autoimmune disease.
Gut mucosal inflammation– Vitamin D is a key player in healing gut mucosal inflammation and suppressing the development of Colitis.
Cancer: Studies suggest that vitamin D may have potential anti cancer effects, by inhibiting proliferation of cancer cells
Sign and symptoms of Vitamin D
Burning in mouth and throat, poor immunity, hyperparathyroidism, insomnia, nervousness,osteoporosis, growth retardation.
Who should supplement Vitamin D?
While it is favourable to get our nutrients via a balanced diet, in some cases supplementation may be needed. In the case of vitamin D, these individuals may be at greater risk of deficiency
- Elderly with little to no sun exposure
- People who cover their skin and have very little sun exposure
- Dark skinned people – The synthesis of Cholecalciferol is less effective in our skin than in caucasians skins
- Individuals with kidney or liver disease (Both the liver and kidneys transform the non active form of Vitamin D into the active form: Calcitriol)
- Individuals with fat malabsorption syndromes such as Cystic fibrosis. Vitamin D being a fat soluble vitamin,it requires fat for absorption.
- Individuals with inflammatory bowel disease such as Chron’s,Colitis
Diagnostic: If you are suspecting a vitamin D insufficiency, contact your gp or natural health practitioner who will be able to assess your symptoms and guide you towards the next step
Vitamin D Supplement. Studies have shown that D3 is the most potent (3x more) source of vitamin D, therefore it is favoured for supplements. The liquid form of Vitamin D seems to be best absorbed by the body.
How much? This will depend on the cause of your deficiency and how long you are supplementing for.
Vitamin D toxicity is rare but can happen via supplementation.
Please always consult your doctor or natural practitioner before supplementing Vitamins and Minerals. They will be able to check for drug nutrient interactions if you are currently taking any medication , as well as adequate dosages for you.