Vitamin D is a micronutrient and like all other micronutrients, it is required in a small amount, but performs several essential functions in the body.
Vitamin D is a fat-soluble vitamin that among other functions, also helps regulate the amount of calcium and phosphate in our body. Both these nutrients are an essential component for keeping bones, muscles, and teeth in a healthy state. Our bodies can only absorb calcium (important component of bones), in the presence of Vitamin D.

Why is Vitamin D important?

There are several functions of Vitamin D in the body, the important ones include:

•    Helps the body absorb and retain calcium and phosphate
•    Reduces cancer cell growth
•    Helps control infections
•    Reduces inflammation
•    Supports brain cell activity

How do we get Vitamin D?

Vitamin D is called the sunshine vitamin, because our body synthesizes this vitamin on exposure to sunlight. 

It’s important to understand that sunlight exposure depends on our geographic location and also the seasons. Dark-skinned individuals and people of older age may not be able to get enough vitamin D through sunlight. Only few foods naturally contain vitamin D, though some may be fortified with this vitamin. The best way to replenish vitamin D in our body is by taking supplements. 

Vitamin D supplements are available in two forms: vitamin D2 (also called “ergocalciferol” or pre-vitamin D) and vitamin D3 (also known as “cholecalciferol”). Both ergocalciferol and cholecalciferol are produced naturally in the presence of UVB (Ultraviolet-B) rays, thus giving it the name “sunshine vitamin.” The best time for obtaining vitamin D from sunlight is around mid-day. If you spend a total of 20-25 minutes in the sun, it will be sufficient to get exposure for obtaining vitamin D. The only difference between the two forms of this vitamin lies in the fact that vitamin D3 is produced in animals, including human beings whereas vitamin D2 is produced in plants and fungi.

What is Vitamin D3?

Vitamin D3 or cholecalciferol is an active form of vitamin D. It is also consumed as a dietary supplement when the amount of vitamin D available in foods is insufficient. Common vitamin D3 deficiency symptoms include fatigue, bone pain, muscle weakness, aches, or cramps, and changes in mood and behavior such as depression. Some of the notable benefits of vitamin D3 are maintenance of healthy bones, muscles, and nerves, and supporting the immune system of our body. Along with calcium, it helps in the prevention and treatment of bone diseases such as rickets (in children) and osteomalacia and osteoporosis (in adults). 

Diseases that cause vitamin D deficiency

There are certain medical conditions that can lead to vitamin D deficiency. Some of these are mentioned below:

•    Cystic fibrosis, celiac disease, and Crohn’s disease: These health conditions prevent the body from adequately absorbing vitamin D by the intestines, especially if the condition is left untreated.

•    Liver and kidney disease: Hepatic 25-hydroxylase from the liver and 1-alpha-hydroxylase from the kidneys, are two enzymes that are required for the body to convert vitamin D into a usable form. However, during a liver or kidney disease, a lack of either of these enzymes leads to insufficient levels of vitamin D in your body.

•    Obesity: An increased body mass index (BMI>30) is known to be associated with lower vitamin D levels in the body. Greater the number of fat cells, lesser the chances of vitamin D not being released.

•    The above-mentioned conditions can cause vitamin D deficiency, which is not treated, can lead to: Rickets: Softening of bones in infants and children, characterized by “bow-shaped legs”

•    Osteomalacia: Softening of bones during adulthood that can be made reversible by supplementation

•    Osteoporosis: Bones become porous and brittle in an irreversible way; mostly happens due to old age

Foods high in vitamin D

Some foods are naturally rich in vitamin D3. Best examples are fish liver oils and the flesh of fatty fish. Other than these, egg yolk, beef liver, and cheese contain smaller amounts of vitamin D3. Many mushroom varieties contain vitamin D2 such as commercially grown mushrooms that are exposed to high amounts of UV light. Fruits rich in vitamin D include oranges and banana.

Vitamin D deficiency treatment

If your vitamin D levels are below normal, you can increase it by spending more time outside in the sunlight, by consuming fortified foods such as dairy products and cereals, or by taking additional vitamin D supplements. While vitamin D3 supplement is easily available over-the-counter (OTC), you need a prescription from a healthcare provider for getting vitamin D2 supplements.

How to know if you have vitamin D deficiency?

The most accurate test for finding out how much vitamin D is there in the body is the 25-hydroxy vitamin D test. In this test, a blood sample is taken from a vein in the arm. You do not need to fast (no food and drink) before taking this test. 

25-hydroxy vitamin D normal range

The normal range for this test is measured in nanograms per milliliter (ng/mL). The normal reference range lies between 20-40ng/mL. Sometimes, the recommended level is taken to be between 30-50ng/mL.

A higher-than-normal range indicates that there may be excess vitamin D in the body. This condition is called hypervitaminosis D. This can happen due to excess intake of vitamin D which results in too much calcium in the blood called hypercalcemia. It can lead to kidney damage if left untreated for long.

Although vitamin D levels are known to decline with advancing age, it is recommended to keep the levels within the normal range by taking supplements. This will go a long way in helping you have healthy and strong bones, keeping you away from age-related bone disorders. Let us strive for a long and healthy life, devoid of aches and pains!

‘Vitamin D Deficiency - As common a concern, easier it is to prevent’

Just Follow your basics:

•    Expose your body to day sunlight & NOT just morning sunlight
•    Make sure that when you do that, your 70% of the body is being exposed to sunlight
•    Take Care of your children in the growing age to observe rickets
•    Consume food items rich in Vitamin D, but visit your doctor in case of Vitamin D deficiency in reports – Supplements work faster than diet at such times.
•    Regular Exercise is a must for healthy bones

-    Dr. Hardeek Ghundiyal – MBBS, DNB (Orthopaedics), D. Ortho

Consultant Orthopaedics & Orthopaedic Surgeon, Mumbai
Specialists in Minimal Invasive Joint Replacement Surgery
Consultant at Inlaks Hospital, Nulife Hospital, Shantiniketan Hospital & Parakh Hospital, Mumbai
Ex. Clinical Asst. at Dr. Balabhai Nanavati Hopsital, Mumbai