We hear a lot about vitamins, but not a lot of people know why they are necessary for our body. After reading this article, you would have a better idea about why Vitamin D in particular is important for you!

Vitamin D is a group of fat-soluble compounds mostly found in fish.The most important forms are vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol).

The first one is only exogenous, meaning we cannot synthesize it on our own, while vitamin D3 which is the major natural form can be synthesized by the body under the influence of sunlight exposure (Ultraviolet-radiation) from cholesterol. Individuals in regions with low sunlight exposure are not able to synthesize enough vitamin D to meet their body’s metabolic demand. Only a small group of food contains vitamin D.

Hence, it is recommended to include supplements of vitamin D to their diet. The recommended daily intake for an adult is 15μg and it should not exceed 100μg.


The synthesis of vitamin D is largely under the influence of sunlight exposure (UVB radiation). About 70% of vitamin D is made in the skin and the remaining 30% is from a dietary source. The precursor of vitamin D exists under the skin as 7-dehydrocholesterol (a large molecule). Sunlight exposure (Ultraviolet light) breaks down 7-dehydrocholesterol to dehydrocholesterol (cholecalciferol). Cholecalciferol which is an inactive form of vitamin D is further hydroxylated in the liver and the kidneys into 25-hydrocholecaciferol and 1,25-dihydrocholecalciferol respectively. 1,25-dihydrocholecalciferol (Calcitriol) is the only biologically active form of vitamin D.  

vitamin D EFFECTS

Vitamin D is necessary for our body as it increases intestinal absorption of calcium, magnesium, phosphate, and zinc. These are very important electrolytes in our body for a number of reasons. Calcium is used during bone formation and it is also a mediator for muscle contraction, neuromuscular transmission, cardiac automaticity, nerve function, blood coagulation, cell division and movement.


Research on vitamin D use for specific conditions

1. Inherited disorders:

Vitamin D supplements can be used to help treat inherited disorders resulting from an inability to absorb or process vitamin D, such as familial hypophosphatemia.

2. Osteomalacia:

Vitamin D supplements are used to treat adults with severe vitamin D deficiency, resulting in loss of bone mineral content, bone pain, muscle weakness and soft bones (osteomalacia).

3. Osteoporosis:

Studies suggest that people who get enough vitamin D and calcium in their diets can slow bone mineral loss, help prevent osteoporosis and reduce bone fractures.

4. Rickets:

This rare condition develops in children with vitamin D deficiency. Supplementing with vitamin D can prevent and treat the problem.

5. Cancer:

Vitamin D has been under the lens of research for a while now about its anti-cancer properties. Mechanism and outcomes are not fully clear but there has been little evidence, vitamin D decreases mortality from cancer and development of certain cancers (eg. Colon cancer).

6. Infectious disease:

The action of vitamin D on the innate immune system helps reduce the risks of infections (especially viral). Tuberculosis infection is commonly encountered in patients with vitamin D deficiency.

7. Diabetes mellitus:

Some claims have been made with little evidence that, vitamin D deficiency may be a risk for developing diabetes mellitus.



Some foods that contain a high level of vitamin D are:

1. Fatty fish like; tuna, mackerel and salmon
2. Orange juice
3. Soy milk
4. Cereals
5. Beef liver
6. Cheese
7. Egg yolk
8. Mushrooms

So, remember to include it in your diet! Your bones will thank you in the long run!