What is the Difference Between Vitamin D and Calcium

Vitamin D and calcium are both essential nutrients for maintaining healthy bones and overall well-being, but they serve different functions in the body. Vitamin D is a fat-soluble vitamin, whereas calcium is an element.

What is the difference between vitamin D and calcium? Calcium helps build and maintain strong bones and teeth, while vitamin D helps absorb and regulate calcium in the body.

Key Areas Covered

1. What is Vitamin D  
      – Definition, Function
2. What is Calcium
      – Definition, Function
3. Similarities Between Vitamin D and Calcium
      – Outline of Common Features
4. Difference Between Vitamin D and Calcium
      – Comparison of Key Differences
5. FAQ: Vitamin D and Calcium
      – Answers to Frequently Asked Questions

Key Terms

Vitamin D, Calcium

Difference Between Vitamin D and Calcium - Comparison Summary

What is Vitamin D

Vitamin D is an essential nutrient for the body. It can be obtained from sunlight and dietary sources such as fatty fish (e.g., salmon, mackerel), fortified foods (e.g., milk, cereal), and supplements. When our skin is exposed to sunlight, it produces vitamin D3, which is then converted into its active form in the liver and kidneys. The amount of vitamin D synthesized in the body depends on geographical location, season, time of day, cloud cover, sunscreen use, and skin pigmentation.

The health benefits of vitamin D include playing a role in immune function, cardiovascular health, mood regulation, and cancer prevention, as well as aiding in bone mineralization and the growth and regulation of calcium and phosphorus absorption.

Vitamin D

When the required levels of vitamin D are not present in the body, a condition called vitamin D deficiency occurs. This condition is caused by factors such as indoor lifestyles, limited sun exposure, certain medical conditions, and dietary habits. Symptoms of deficiency may include fatigue, muscle weakness, bone pain, and increased susceptibility to infections.

What is Calcium

Calcium is a vital mineral found in the body, especially in bones and teeth and in smaller amounts in the blood, muscles, and other bodily tissues. It is essential for the formation and maintenance of strong bones and teeth by providing structural support. Adequate levels of calcium prevent conditions like osteoporosis, which weakens bones and increases the risk of fractures.

Calcium is also involved in muscle contraction and relaxation. It interacts with proteins within muscles to enable the contraction process, allowing for activities such as walking, running, swimming, and the beating of the heart.


Calcium also plays a key role in the transmission of nerve impulses throughout the body. It helps regulate the release of neurotransmitters, which are chemical messengers that allow nerve cells to communicate with each other and with muscles.

Additionally, calcium assists in the activation of many proteins involved in clot formation, promoting the creation of a stable blood clot. Calcium ions also act as signaling molecules within cells, regulating processes such as cell growth, division, and apoptosis.

Similarities Between Vitamin D and Calcium

  1. Vitamin D and calcium are essential for maintaining strong and healthy bones.
  2. Both contribute to proper muscle performance and strength.
  3. Both nutrients play a role in nerve function.

Difference Between Vitamin D and Calcium


  • Vitamin D is a fat-soluble vitamin, whereas calcium is an element and a mineral required for the body.


  • Vitamin D can be obtained from sunlight exposure, certain foods like fatty fish and fortified dairy products, and supplements, while calcium is found in dairy products, leafy greens, fortified foods, and supplements.


  • Calcium is a vital mineral necessary for building and maintaining strong bones and teeth. It also plays a role in muscle contraction, nerve transmission, and blood clotting. Vitamin D helps in the absorption and regulation of calcium and phosphorus in the body. In addition, it supports immune function, mood regulation, and cardiovascular health.


  • Vitamin D is primarily absorbed through the skin when exposed to sunlight and then metabolized in the liver and kidneys, while calcium is absorbed in the intestines.


  • Vitamin D deficiency can lead to weakened bones, increased risk of fractures, and potential problems with immune function and mood regulation, while calcium deficiency can result in osteoporosis, muscle cramps, and weakened teeth and bones.


Both vitamin D and calcium are essential nutrients for maintaining strong bones, but they differ in their chemical nature and sources. Vitamin D, a fat-soluble vitamin, is primarily obtained from sunlight exposure and certain foods, while calcium, an element, is found in dairy products, leafy greens, and supplements. This is the main difference between vitamin D and calcium. Deficiency in either can lead to various health issues, including weakened bones and muscle problems.

FAQ: Vitamin D and Calcium

1. Is it better to take vitamin D or calcium?

You have to take both vitamin D and calcium because they work together to maintain bone and muscle health. Your body needs vitamin D to absorb calcium effectively, which is crucial for keeping your bones and muscles, including your heart, healthy and strong.

2. What are the signs of low vitamin D?

  • Muscle pain.
  • Bone pain.
  • Increased sensitivity to pain.
  • A tingly, “pins-and-needles” sensation in the hands or feet.
  • Muscle weakness in body parts near the trunk of the body, such as the upper arms or thighs.

3. Does low vitamin D cause high calcium?

When vitamin D level is low, the absorption of calcium in the intestines becomes less, which then causes the level of calcium in the blood to go down.

4. What is the best time to take calcium?

Calcium should be taken in the morning (about 1 hour after breakfast) or in the afternoon with plenty of water, giving us the opportunity to be exposed to more sunlight (the skin synthesizes vitamin D for the body). ), which helps to absorb calcium more efficiently.

5. Who should avoid calcium?

Calcium supplements aren’t for everyone. For instance, if you have a health condition that causes excess calcium in your bloodstream (hypercalcemia).


1. “Vitamin D – Uses, Side Effects, and More.” WebMD.
2. “Benefits and sources of calcium.” Medical News Today.

Image Courtesy:

1. “Vitamin D deficiency in 76 percent of Indians, can cause these diseases” By (CC BY 2.0 DEED) via Flickr
2. “Sources of Calcium” By Brookepinsent – Own work (CC BY-SA 4.0) via Commons Wikimedia

About the Author: Hasa

Hasanthi is a seasoned content writer and editor with over 8 years of experience. Armed with a BA degree in English and a knack for digital marketing, she explores her passions for literature, history, culture, and food through her engaging and informative writing.

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