Calcium and vitamin D are the allies of good bone health

What if consuming vitamin D in conjunction with calcium led to better bone health? Learn more about the benefits of food synergies…

-Calcium, a key mineral in the human body

The nutritional benefits of calcium

Calcium is the most abundant mineral in the body. In terms of distribution, 99% of calcium is found in the bones and teeth. It also circulates in free form in the blood.

Beyond its presence in the skeleton, calcium is involved in muscle contractions. It also plays a role in the normal functioning of the nervous system.

Regarding daily intake, the European Food Safety Agency (EFSA) recommends 860 mg/day for 18-24-year-olds and 750 mg/day for people over 25. When the diet does not provide enough calcium, there is an increased risk of fractures and loss of bone density. Conversely, an excess of calcium leads to the appearance of kidney stones. 

Food sources of calcium

The main problem with calcium is its low rate of assimilation. Indeed, even if some foods can be rich in calcium, the quantity of calcium that effectively passes into the bloodstream remains low. For example, cheese contains an average of 550 mg of calcium per 100 g with an absorption rate of about 30%. Conversely, kale contains about 94 mg of calcium per 100 g but has an absorption rate of over 50%. It is therefore essential to vary the sources of calcium to get the best intake. 

Vitamin D, a solar vitamin

The nutritional interests and benefits of vitamin D

Vitamin D is a so-called fat-soluble vitamin, i.e., it is soluble in fat. As a result, the body stores this vitamin in the fatty tissues of the body. Vitamin D exists in two forms: first, vitamin D2, also known as ergocalciferol. Plants and vegetation produce this vitamin. The second form is called vitamin D3, also known as cholecalciferol. It comes from animal sources, but also certain lichens. 

The skin also produces vitamins following exposure to UV-B rays. However, the time of exposure, the pigmentation, the intensity of the rays and the latitude determine and condition the quantities of vitamin D that the skin can synthesize.

In terms of health benefits, vitamin D plays a role in the immune system, but also bone health.

Food sources of vitamin D

As the synthesis of vitamin D by the body decreases with age and many factors influence the quantities produced, the diet must provide this vitamin. Fatty fish such as sardines, salmon, and herring contribute to a good intake of vitamin D. Other foods such as egg yolks, milk, and butter are also sources of vitamin D, but in much smaller quantities. 

The power of food synergies

What is a nutritional synergy?

Food synergy refers to the cooperation between different nutrients at the body level.  This synergy is evaluated from a qualitative as well as quantitative point of view. Mathematically, this would translate into the following equation: 1+1=3.

The human body consists of a constant interactive balance. This means that nothing is categorized exclusively as man likes to organize things. In the body, all mechanisms and reactions operate simultaneously. Thus, the nutrients present in food interact with each other to reinforce or inhibit each other.

The value of joint calcium and vitamin D intake

A recognized dietary synergy exists between vitamin D and calcium. As mentioned above, these two nutrients play a role in the bones. In addition, the body has some difficulty in properly assimilating calcium from food.

Vitamin D, on the other hand, contributes to the assimilation and fixation of calcium in the bones. Therefore, eating foods rich in vitamin D along with foods rich in calcium guarantees a better calcium intake for the body. Think about it at your next meal!


Foods are diverse sources of nutrients, each with specific benefits. For example, the calcium found in dairy products or certain plants helps build the skeleton. Vitamin D, on the other hand, is found in fatty fish and is involved in the immune system and bones. Taken together, these two nutrients contribute to reinforcing their effects on health. So don’t hesitate to adopt a varied and balanced diet, it’s the key to success!


Key take-home messages

  • Calcium is present mainly in the bones and teeth
  • Calcium absorption by the body is not optimal
  • A nutritional synergy refers to the joint action of two nutrients for greater health benefits
  • Vitamin D contributes to the assimilation and fixation of calcium in the bones


DRV Finder, European Food Safety Agency, 2019

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