Sources and Importance of Vitamin D
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Sources and Importance of Vitamin D

Written by
Dr. Krutika Shrikant Ingle
and medically reviewed by iCliniq medical review team.

Published on May 29, 2017 and last reviewed on Dec 16, 2022   -  5 min read


This article discusses the importance of vitamin D, vitamin D deficiency, and its natural sources.

Sources and Importance of Vitamin D

What Is Vitamin D?

Vitamin D, one of the fat-soluble vitamins, is essential for our body to absorb calcium properly and manage bone and muscle health. We receive most of the vitamin D we require from sunlight. Small amounts are also found in foods like fatty fish, fortified margarine, and milk. Vitamin D is important for the general health of our body, particularly for bones.

What Are the Sources of Vitamin D?

  • Sunlight is the essential and abundant source of vitamin D available.

  • Non-vegetarian foods are also the second most important source of vitamin D. Examples are fish liver oils like cod liver oil, egg yolk, dairy products, and fatty fishes, like tuna and salmon fish.

  • Vegetarian food has very low amounts of vitamin D. Some examples are mushrooms, broccoli, avocado, tofu, and fortified cereals.

Which Foods Are Rich in Vitamin D?

  • Cod Liver Oil:

One tablespoon of cod liver oil may contain 340% of vitamin D. That is why cod liver oil is considered one of the good sources of vitamin D. It is also a good source of vitamin A.

  • Swordfish:

Swordfishes are rich in vitamin D. Three ounces of cooked swordfish can provide 166% of the vitamin D.

  • Sockeye Salmon:

Three ounces of this sockeye salmon fish contains 131% vitamin D. This fish is also a great source of thiamin, niacin, and vitamin B12.

  • Tuna Fish:

Tuna fish is a good source of vitamin D as 3.5 ounces of canned tuna contains 34% of vitamin D.

  • Atlantic Cod:

Atlantic cod is another fish that is packed with vitamins and minerals and a food high in vitamin D. One fillet of Atlantic cod will contain 20% of vitamin D.

  • Beef Liver:

Beef liver is a good source of vitamin D. 2.5-ounce cooked beef liver contains around 6% of vitamin D.

  • Pork:

Pork chops are one of the foods rich in vitamin D. An 8-ounce pork chop will contain 15% of vitamin D.

  • Chicken Breast:

Chicken breast is another food with vitamin D. Three ounces of roasted chicken breast cover 1% of the vitamin D. It is a fantastic source of zinc, lean protein, and B vitamins.

  • White Mushroom:

A half-cup of raw, sliced white mushrooms that are exposed to UV (ultraviolet) light contains about 46% of vitamin D.

  • Eggs:

One large scrambled egg contains 6% of vitamin D. Vitamin D is present in the yolk of the egg. Therefore, some vegetarians, like ovo-vegetarians (people who eat eggs but not dairy) and lacto-ovo-vegetarians (eat both eggs and dairy products), might depend on eggs to meet their dietary needs.

  • Milk:

To reap the benefits of vitamin D3, include fortified milk in your diet. One cup of fortified milk with 2% fat contains around 13%–18% of vitamin D. Milk is also a great source of riboflavin, vitamin B12, calcium, and phosphorus.

  • Yogurt:

Overall, yogurt is highly nutritious as it contains various B vitamins, calcium, phosphorus, and other minerals. Yogurt is also usually enriched with vitamin D, making it an excellent addition to the vitamin D foods list. A 6-ounce container of fortified yogurt will provide you with around 13% of vitamin D.

  • Margarine:

Margarine has a taste similar to butter, but it is made from vegetable oil. One tablespoon of fortified margarine will contain 10% vitamin D. Be cautious while buying fortified margarine because some products may contain partially hydrogenated oils that should be avoided.

  • Cheddar Cheese:

There are not enough vegetables or fruits with vitamin D. Few vegetarians depending on food for vitamin D, can take cheddar cheese. Three ounces of cheddar cheese contain 6% of vitamin D.

  • Cereals:

A half-cup of certain fortified cereals may contain 17% of vitamin D.

  • Orange Juice:

Orange juice is rich in vitamin D. A cup of fortified orange juice may contain 12% of vitamin D. It also contains vitamin C, folate, and potassium.

Some Important Facts About Vitamin D Are as Follows:

  • Vitamin D from the sunlight is absorbed into our body through the skin. Hence, its absorption is decreased by using sunscreen lotions.

  • Vitamin D is activated in our body in the liver and the kidney. Hence, its deficiency can be seen in people suffering from liver or kidney diseases.

  • Vitamin D increases the absorption of calcium from the intestines.

  • The active form of vitamin D has an anti-proliferative effect on keratocytes (skin cells), breast cancer cells, and prostate cancer cells. Hence, it is seen to be protective against these cancers.

  • Vitamin D helps in warding off chronic ailments like diabetes mellitus, heart diseases, and depression.

Long-Standing Vitamin D Deficiency: It decreases calcium levels, accompanied by impaired mineralization of the skeleton and proximal myopathy. Under-mineralization of the bones can lead to uncomplicated fractures, osteoporosis, and complicated fractures. Sometimes severe vitamin D deficiency can also lead to other diseases. Vitamin D deficiency can cause rickets in children and osteomalacia in adults.


Rickets is a disorder that occurs in the bones of children. In this disorder, the bones will become soft and more prone to fractures. Bones become weak due to an inadequate supply of nutrients, particularly vitamin D3. It can also be caused due to lack of calcium and phosphate in the body.

Signs and Symptoms of Rickets

Vitamin D is essential to absorb calcium from food. Therefore, lack of calcium and vitamin D or failure to absorb the same can cause rickets. It can cause deformities in the skeleton like,


Osteomalacia is the softening of bones due to the deficiency of vitamin D. When there is a lack of vitamin D, the body cannot absorb calcium from the food we eat, thus weakening the bones. If you have osteomalacia, you may have symptoms like:

  • Pain.

  • Stiffness.

  • Easily breaking bones.

  • Feeling tired.

  • Trouble getting up after sitting or walking upstairs.

  • Weak muscles in the arms and thighs.

Diagnosis of Vitamin D Deficiency: The most specific screening test in otherwise healthy individuals is serum 25-hydroxy vitamin D levels.

Treatment for Vitamin D Deficiency: The treatment includes supplementation with Vitamin D and Calcium. It is important to note that the self-administration of medications should be avoided, as vitamin D is a fat-soluble vitamin. Hence, the excess amount is not easily excreted out of the body and would lead to vitamin D toxicity. Therefore, it is recommended to get treated under the supervision of your physician.

Frequently Asked Questions


What Foods Are High in Vitamin D?

Foods that are high in Vitamin D are:
- Salmon.
- Cow's milk.
- Herring fish.
- Mushrooms.
- Oatmeal.
- Canned Sardines.
- Beef liver.
- Halibut (fatty fish).
- Soy milk.
- Mackerel.
- Cod liver oil.
- Cheese.
- Orange juice.
- Red meat.
- Canned tuna.
- Cereals.
- Egg yolks.


What Happens When Your Vitamin D Is Low?

Low vitamin D can lead to:
a) Loss of bone density, contributing to-
- Osteoporosis.
- Fractures (broken bones).
b) Rickets in children (soft bones and easy to bend).
c) Osteomalacia in adults (bone pain).
d) Gastrointestinal diseases.
e) Renal diseases.
f) Liver diseases.


What Are the Benefits of Vitamin D?

Vitamin D helps in:
- Absorption of calcium.
- Absorption of phosphorus.
- Boosting energy levels.
- Facilitates the function of the normal immune system.
- Regulates the neuromuscular system.
- Regulates insulin levels.
- Growth and development of bones.
- Resisting against certain diseases.
- Build out normal growth of teeth.
- Keeps skin healthy.
- Stimulates cell growth.
- Keeping the muscles healthy.
- Enhances the mood.


Do Bananas Have Vitamin D?

Bananas are a great source of magnesium, and it plays an important role to activate vitamin D in the body. There is 0.00 IU of vitamin D in the 100-gram portion of bananas.


What Drink Is High in Vitamin D?

Cow's milk is naturally a good source of,
- Calcium.
- Phosphorous.
- Vitamin B.
In many countries, cow's milk is fortified with vitamin D, and it contains 115 to 130 IU per 237 ml.


How Many Minutes of Sun Do You Need for Vitamin D?

Regular sun exposure for 10 to 30 minutes every day helps to get enough vitamin D. But the exposure time to the sun depends on the skin type you have. If someone can burn easily in the sun with skin type 1 or 2, it needs only five minutes of sun exposure per day, but if you are the one with darker skin type with 5 or 6, you will need more time of sun exposure. But the regular time of sun exposure should be before 11 AM and after 4 PM.


Does Vitamin D Affect Sleep?

It is said that vitamin D levels affect the quality of sleep due to the inverse action on the sleep hormone melatonin. The low levels of vitamin D in the blood lead to a higher risk of,
- Sleep disturbances.
- Poor sleep quality.
- Reduction in the duration of sleep.


When Should I Take Vitamin D?

Vitamin D should be taken in the morning because usually, we will get vitamin D naturally with the help of the sun, and we will be synthesizing it during the day. So, if on vitamin supplements, most importantly, try to fit vitamin D into your routine alongside breakfast, or you can also add it as a bedtime snack if it does not interfere with sleep.


How Long Does It Take to Correct Vitamin D Deficiency?

Bringing back the vitamin D levels to normal will take 6 to 8 weeks of time by the doctor, and this depends on,
- Age of the patient.
- How low is the vitamin D level in the blood?
- Causative factor for the low vitamin D levels.


How Much Vitamin D Should Be Taken per Day?

The recommended intake of vitamin D is 400 to 800 IU per day or 10 to 20 micrograms per day. In order to maintain an optimal blood level higher vitamin D intake of 1,000 to 4,000 IU per day or 25 to 100 micrograms per day is required.


Does Vitamin D Help Hair?

Vitamin D deficiency is linked to alopecia areata, which is an autoimmune condition causing patchy hair loss. Having normal vitamin D levels helps to stimulate hair follicles and in the growth of affected hairs.

Article Resources

Last reviewed at:
16 Dec 2022  -  5 min read




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