Vitamin D and collagen: what vitamin D does in your daily portion

Why is there vitamin D in a collagen portion?

Vitamin D is in a collagen portion because it brings a different job description from the collagen, with authorised wording about bones, muscle function and teeth rather than your face. Core^™ lists 60 µg of vitamin D per portion, next to 11,000 mg of hydrolysed marine collagen.¹

It is there for breadth, because the EU list of permitted health claims gives vitamin D wording for bones, muscle function and teeth.² Core^™ includes it.

The rest of this guide takes the vitamin D line on the label and reads it slowly, using only what the law allows the vitamin to say and what the published opinions behind that wording concluded.

What is vitamin D?

Vitamin D is a fat-soluble vitamin, and one the body produces for itself. The NIH fact sheet on vitamin D describes it being made when ultraviolet rays from sunlight strike the skin.³

From there it goes to work elsewhere in the body. The same fact sheet says vitamin D promotes calcium absorption in the gut and helps keep blood calcium and phosphate at adequate concentrations.³

The fact sheet adds that vitamin D is needed for bone growth and bone remodelling, and for the normal development and growth of muscle fibres.³

Image slotWoman in cream linen walking across a sunlit terrace with a small glass of berry-red drinkassets/img/blog/vd-shot.webp

What is vitamin D authorised to say?

Vitamin D is authorised to speak about bones, muscle function, teeth, calcium and phosphorus, blood calcium and the immune system, in wording taken from the EU list of permitted health claims, the only wording a food may use to describe a vitamin's benefit.² The phrases are fixed, and a careful brand prints them unchanged. The table gives six of them for vitamin D, one line per row.

Read down the first column and you get a map of the vitamin. Three rows name structures you can point to: skeleton, muscle, teeth. The calcium and phosphorus rows name two minerals, and the last row is the body's defences, which we cover with the other immune nutrients in Core^™ in our article on vitamins and the immune system.

What did EFSA conclude?

EFSA, the European Food Safety Authority, concluded that dietary vitamin D intake has an established cause and effect relationship with normal bone and teeth and, in a later opinion, with normal muscle function. Each authorised phrase traces back to a scientific opinion like these, from a panel that weighs the evidence before a claim reaches the list.

For bone, the opinion also gives its reasoning. Vitamin D is required for efficient calcium absorption and for maintaining normal blood calcium and phosphate, which are needed for the normal mineralisation of bone and teeth.⁴

That reasoning ties the table together. The calcium rows describe the route, and the bones and teeth rows describe where it leads. The panel reached its cause and effect conclusion for bone and teeth in 2009 and for muscle function in 2010.

If bones and muscle are your main interest, our article on bones and muscles after menopause looks at both vitamins involved from that reader's side.

How much vitamin D is in Core^™?

Each portion of Core^™ has 60 µg of vitamin D.¹ The label states it as an amount, in micrograms, and that is the figure to go by.

• One portion a day. Shake the pack, pour a portion into the cap and drink it straight, or stir it into water or a smoothie.
• Nothing extra to remember. The vitamin D is already in the liquid with the collagen.
• Fridge once opened. Core^™ comes in a 500 ml pack. Keep it in the fridge once opened.

There is one more vitamin D connection on the label. Pantothenic acid (vitamin B5) contributes to normal synthesis and metabolism of steroid hormones, vitamin D and some neurotransmitters.² Core^™ has 5 mg of it per portion.¹

How does vitamin D sit beside vitamin C?

Vitamin D and vitamin C meet at bones and teeth: vitamin D's wording is about maintaining them, while vitamin C's wording is about normal collagen formation for their normal function. That shared ground is where the collagen comes back in. The same portion of Core^™ has 120 mg of vitamin C.¹

• Vitamin C contributes to normal collagen formation for the normal function of bones.²
• Vitamin C contributes to normal collagen formation for the normal function of cartilage.²
• Vitamin C contributes to normal collagen formation for the normal function of teeth.²

Set those beside the vitamin D table and bones and teeth each appear under both vitamins, from different directions. Cartilage appears under vitamin C only.

A peer-reviewed review states that type I collagen is the most common type in skin, bone, teeth and tendon, while type II is present in cartilage.⁶ That describes the collagen your own body makes and where it sits.

Each vitamin keeps to its own wording. For the vitamin C half, see how vitamin C and collagen work together.

Does vitamin D do anything for skin and hair?

The EU list gives vitamin D wording for bones, muscle function, teeth, calcium and phosphorus, blood calcium and the immune system, and none for skin or hair.²

Those lines are held by other nutrients in the same pack, and each keeps its own wording:

• Hair. Biotin contributes to the maintenance of normal hair. Selenium contributes to the maintenance of normal hair.²
• Skin. Biotin contributes to the maintenance of normal skin. Vitamin C contributes to normal collagen formation for the normal function of skin.²

A formula with several nutrients divides the work this way, with each one there for the job it is authorised to name. You can read the biotin side in full in our biotin article.

What did women in our trial report?

In our user trial, 99% of women found our liquid marine collagen easy to include in their daily routine, 95% felt the appearance of their skin improved and 86% reported healthier hair. The 106 women took the whole drink every day for 8 weeks and reported what they noticed.¹ These figures describe the complete formula as the women experienced it. They are not readings for any single vitamin.

We chose the first tile because nearly every woman in the trial found the habit easy to keep. Participants also reported more energy and better joint flexibility.¹

The women in that trial reported visible results in as little as 4 weeks, with further improvement by week 8.¹

Questions about vitamin D and collagen