Can You Take Calcium and Vitamin D Together?

Calcium and vitamin D are almost always mentioned in the same breath – and for good reason. But does that also mean you absolutely have to swallow them at the same time? And how much is actually sensible? The core answer first:

Yes, you can take calcium and vitamin D together without any problem – the two form a real team when it comes to the bones, because vitamin D contributes to the normal absorption and utilisation of calcium. Precise joint timing is not necessary here, because vitamin D is stored in the body.

Why these two belong inseparably together

The connection is functionally particularly close – closer than with most other nutrient pairs. You can think of it like this: calcium is the building material for the bones, but without vitamin D this material doesn't arrive properly. Vitamin D contributes to a normal absorption and utilisation of calcium and phosphorus as well as to a normal calcium level in the blood. It essentially opens the door for calcium into the body.

The recognised functions dovetail:

• Calcium contributes to the maintenance of normal bones and teeth as well as to a normal muscle function.
• Vitamin D contributes to the maintenance of normal bones, teeth and muscle function as well as to a normal function of the immune system.

Without sufficient vitamin D, the body can utilise supplied calcium less well. That's why both are found so frequently together in supplements for the bones. More on the topic in Nutrients for the bones.

Where the body gets calcium and vitamin D from

We take in calcium above all through dairy products, green vegetables such as broccoli and kale as well as through calcium-rich mineral water. Vitamin D is a special case: the body forms it itself via the skin with sufficient sunlight. Especially in the dark season this own production is low in our latitudes, which is why many people supplement in winter. Through food alone the vitamin D requirement is difficult to cover – fatty sea fish is one of the few noteworthy sources. Basics on this in Calcium: effect, daily requirement, sources.

Do you have to take both at the same time?

No, precise joint timing is not required. Vitamin D is fat-soluble and is stored in the body over days to weeks, so its contribution to calcium utilisation doesn't depend on a minute-precise intake. Taking them together is nevertheless practical, because that way you don't forget either of the two. Since vitamin D is fat-soluble, you ideally take it with a fat-containing meal – details on this in Vitamin D: drops or capsules.

Splitting calcium correctly

An often overlooked practical point: the body tends to absorb calcium better in smaller portions than in one very large single dose. Anyone supplementing a higher daily amount can therefore spread this over two doses – for example morning and evening. Also remember that the diet already delivers calcium; you should count that towards the total amount so as not to dose unnecessarily high. How and when to best take calcium is explained in Calcium: when and how to take it and Calcium: morning or evening.

Important separation note: calcium and iron

A factual point on timing: calcium can inhibit the absorption of iron in the intestine. Anyone supplementing both should therefore take them at different times – for example iron in the morning and calcium later in the day. Background in Separating iron and calcium. With larger amounts of magnesium, too, calcium partly shares the absorption pathways; an overview on this is in Calcium and magnesium: together or separately. If an iron deficiency is suspected, please have this clarified by a doctor before you supplement iron permanently.

Vitamin K2 as a sensible addition

Around calcium and vitamin D a third name often comes up: vitamin K2. Vitamin K contributes to the maintenance of normal bones and to a normal blood clotting. That's why vitamin D and K2 are readily offered together when it comes to the bones. The idea behind it: D ensures that calcium is absorbed, K2 plays a role in where in the body it ends up. Why this combination is worthwhile can be read in Vitamin D and K2 together and Vitamin D3 K2 combination.

What research is investigating

Well proven and textbook knowledge is the central role of calcium for the bone structure and the role of vitamin D in its absorption and utilisation. Around this duo, research looks in particular at the supply situation in various phases of life – such as with advancing age or with low sun exposure – and at the interplay with vitamin K2 in bone metabolism. It is also established that the body's own vitamin D formation declines considerably in winter.

For whom the topic is particularly in focus

Certain life situations bring calcium and vitamin D more strongly into view. With advancing age the ability to form vitamin D via the skin declines, and anyone who gets outside little gets less sun anyway – one reason why the duo is often a topic for seniors (more in Vital substances from 50). Anyone avoiding dairy products, too – for example with a vegan diet or lactose intolerance – should keep an eye on the calcium supply; background in Nutrients with lactose intolerance. And in winter the low vitamin D formation affects practically everyone in our latitudes.

Common mistakes with this duo

We see two stumbling blocks again and again. Firstly: unnecessarily high-dosed calcium, although the diet already delivers a lot – more is not better here, and the total amount counts. Secondly: vitamin D taken on an empty stomach and without fat, whereby the absorption turns out worse than it could be. Both can be easily avoided if you realistically align the calcium amount with your diet and take vitamin D with a fat-containing meal. Further typical mistakes are bundled in Food supplements: common mistakes.

Honestly classified

Established: calcium and vitamin D complement each other particularly closely functionally, their recognised functions are EU-tested, and taking them together is harmless. Realistically, the following remains: not everyone needs additional calcium – anyone who eats a balanced diet covers a large part through food. Supplementation is sensible above all where an actual gap exists. In certain phases of life and with pre-existing conditions, the question of the right amount belongs under medical guidance.

Matching products from Scheunengut

In the category Calcium you'll find supplements for the bones; matching vitamin D products – as drops or capsules – can be discovered under Vitamin D. Anyone wanting to accompany the topic of bones more comprehensively will find something suitable in Joints & bones as well as – for the K2 addition – under Vitamin K. Why vitamin D can frequently be combined with K2 can be read in Vitamin D and K2 together.

Frequently asked questions (FAQ)

Do I have to take calcium and vitamin D at exactly the same time?

No. Vitamin D is fat-soluble and is stored in the body over days to weeks, so its contribution to calcium utilisation doesn't depend on a minute-precise intake. Taking them together is nevertheless practical, because then you don't forget either of the two. You ideally take vitamin D with a fat-containing meal.

Why is calcium often split up?

The body tends to absorb calcium better in smaller portions than in one very large single dose. Anyone supplementing a higher daily amount can therefore spread this over two doses, for example morning and evening. Count the supply from the diet so as not to dose unnecessarily high.

Can I take calcium and iron together?

Better not at the same time. Calcium can inhibit the absorption of iron in the intestine. If you supplement both, take them at different times – for example iron in the morning and calcium later in the day. You should also have an iron deficiency clarified by a doctor before you supplement iron permanently.

What is additional vitamin K2 recommended for?

Vitamin K contributes to the maintenance of normal bones and to a normal blood clotting. That's why it's readily combined with vitamin D around the topic of bones: D supports the absorption of calcium, K2 plays a role in the further bone metabolism. Whether such a combination is sensible for you is best clarified individually.