Why Vitamin D is important?

Calcitriol (or 1,25-dihydroxyvitamin D); ergocalciferol (vitamin D2); cholecalciferol (vitamin D3); calcidiol (25-hydroxyvitamin D)

If you don’t have enough Vitamin D, two things that you could do : consume cod liver oil every morning (get Norway brand, not US brands. It’s way more natural and no sugar), sunbathe every day for 15–20 minutes.

What is vitamin D?

Vitamin D is actually a hormone, not a true vitamin. Individuals with adequate exposure to sunlight do not require dietary supplementation. It is required to absorb calcium from the gut into the bloodstream.

How Vit D is produced
  • Once sunlight hit our body, it activates our skin to convert 7-dehydrocholesterol into Vitamin D3. We can also get Vitamin D2 from plant based food.
  • In the liver, D3 and D2 will be converted into 25-Hydroxyvitamin D3 (calcidiol)
  • Our kidney will then convert D3 (calcidiol) into 1,25 dihydroxyvitamin D3 (calcitriol), active hormone form.
  • Active vitamin D helps increase the amount of calcium the gut can absorb from eaten food into the bloodstream and prevents calcium loss from the kidneys. Vitamin D is important for the formation of new bone.

How Vitamin D is controlled?

Not enough calcium in the bloodstream → parahthyroid glands produce parathyroid hormone → parathyroid hormone increase activity of enzyme that produce active Vit D → once calcium is enough parathyroid glands stop further parathyroid hormone release. Production of Vit D is directly regulated by calcium, phosphate, and calcitriol.

What happens if I have too little vitamin D?

If you have severely low vitamin D levels you are unable to maintain an adequate concentration of calcium in your blood for bone growth. This causes rickets in children and osteomalacia in adults.

As the role of vitamin D as a regulator of other functions throughout the body has emerged, it has been suggested that a lack of vitamin D is linked to an inability to fight infections effectively, muscle weakness, fatigue and the development of diabetes, certain cancers, multiple sclerosis, depression, heart disease, high blood pressure, and stroke, although the direct relevance and mechanisms underlying these responses remain unknown.

Vitamin D deficiency and Autoimmune disease

  • Type 1 diabetes (T1DM): Children with type 1 diabetes have a higher chance of having a vitamin D deficiency compared with the general population.
  • Multiple sclerosis (MS): Current evidence supports that vitamin D deficiency increases the risk of developing MS.
  • Lupus: People with lupus are often photosensitive, causing rashes and possible disease flares when exposed to sunlight. The resulting lack of exposure to sunlight puts them at high risk for vitamin D deficiency.
  • Rheumatoid arthritis (RA): A review of research found that people with the highest vitamin D levels had a 24.2% lower risk of developing RA compared to those with the lowest levels. They also found that there was a higher rate of vitamin D deficiency among people with RA than with the general population, and the activity of RA got worse as the level decreased.
  • Autoimmune thyroid disease (AITD) (Graves’ disease and Hashimoto thyroiditis): In a review of 20 studies, they found that AITD patients has lower levels and were more likely to have vitamin D deficiency compared with controls. In a review of 26 studies of Graves’ disease, they concluded that low vitamin D status may increase the risk of Graves’ disease.

What happens if I have too much vitamin D?

It is very rare to have too much vitamin D. If you have too much vitamin D the level of calcium in your blood may increase and this causes a condition known as hypercalcaemia, which can cause a number of symptoms such as nausea, vomiting, constipation, tiredness, confusion, depression, headaches, muscle weakness, the need to pass urine more frequently and feeling thirsty. However, this condition is very rare.

Possible causes of Vitamin D deficiency. However, lack of sun exposure is still the most common cause.
How we measure Vitamin D deficiency