Vitamin D3
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Vitamin D3
5 micrograms of vitamin D3 from lichen, 100% of the reference intake, and a contribution towards the 10 micrograms the NHS suggests adults consider in winter.
Femme Flora contains 5 micrograms of vitamin D3 (cholecalciferol) from lichen, which is 100% of the Nutrient Reference Value. It carries seven authorised health claims in Great Britain, including that vitamin D contributes to the normal function of the immune system. NHS advice is that adults in the UK consider 10 micrograms a day between October and March, when British sunlight is too weak for the skin to make enough; ours counts towards that figure rather than replacing it.
How we grade this one
Vitamins and minerals are not graded A to E. They sit on the other track: a health claim for them has either been through formal scientific assessment or it has not. That is a different question from how many trials exist.
Vitamin D carries seven health claims that have passed scientific assessment. It is also the only ingredient in either product where official UK advice names a higher number than we carry, and it would be straightforward to leave that unsaid. Section 3 says it instead, because a page that only mentions the figures flattering to us is not worth reading.
1 · What is in the capsule
| Amount | % NRV | Note | |
|---|---|---|---|
| Vitamin D3 · cholecalciferol | 5 µg | 100% | = 200 IU |
| NHS winter advice · for comparison | 10 µg | 200% | = 400 IU, October to March |
The reference intake and the public health advice are two different numbers, and this is the clearest case of it anywhere in our range. 100% NRV sounds complete. It is half of what the NHS suggests you consider in winter.
2 · What vitamin D is, and why Britain is a special case
Vitamin D is unusual among vitamins because the main source is not food. Skin makes it from UVB in sunlight, and dietary sources are comparatively few — oily fish, egg yolk, and fortified foods such as some spreads and cereals.
The UK sits too far north for that to work year-round. Between roughly October and March the sunlight reaching British latitudes does not contain enough UVB for the skin to make vitamin D, whatever the weather does. It is a matter of the angle of the sun rather than how bright the day is.
That is why UK advice is different from advice in sunnier countries, and why vitamin D is the one nutrient where where you live changes the answer.
3 · Our dose is lower than the NHS figure
The plainest thing this page has to say, and the least flattering.
NHS advice is that everyone in the UK consider taking a daily supplement containing 10 micrograms of vitamin D during the autumn and winter, and that some people consider it year-round. Femme Flora carries 5 micrograms.
So this product on its own does not meet that advice. It supplies 100% of the Nutrient Reference Value, which is the figure used to calculate label percentages — but the reference intake and the public health recommendation are not the same number, and on this nutrient they differ by a factor of two.
Why 5 micrograms: Femme Flora is an everyday formula, and its vitamin D is set at 100% of the reference intake, alongside the live cultures and three other vitamins. It is designed to sit alongside a normal diet rather than to replace a dedicated winter vitamin D supplement, which is a different kind of product.
What follows from that is practical. If you are following NHS advice through the winter, a dedicated vitamin D supplement is the way to do it, and ours counts towards the total rather than replacing it. We would rather tell you that than let 100% NRV imply a job it is not doing.
4 · D3 and D2, and where D3 comes from
Vitamin D exists in two supplemental forms. D3 is cholecalciferol, the form the skin makes; D2 is ergocalciferol, produced by certain fungi. D3 is generally the more effective at raising and maintaining vitamin D levels in the blood, and it is the form we use.
One point of origin worth knowing. Most commercial D3 is derived from lanolin, which comes from sheep wool and is therefore not suitable for vegans. Vegan D3 is produced from lichen instead. The D3 in Femme Flora is lichen-sourced, confirmed in a written vegan declaration from our manufacturer, received 4 November 2026 and logged in What’s new.
5 · The seven claims
Reproduced exactly as written. We do not reword them and we do not add to them.
- Vitamin D contributes to the normal function of the immune system
- Vitamin D contributes to the maintenance of normal bones
- Vitamin D contributes to the maintenance of normal muscle function
- Vitamin D contributes to the maintenance of normal teeth
- Vitamin D contributes to normal absorption/utilisation of calcium and phosphorus
- Vitamin D contributes to normal blood calcium levels
- Vitamin D has a role in the process of cell division
Three further claims exist and none of them applies to us. Two concern children, and one concerns reducing the risk of falling in people over 60, which carries its own separate conditions. We do not use any of the three.
They apply from a threshold of 15% of the reference intake. We carry 100%.
What we do not claim
- We do not claim this product meets NHS vitamin D advice for the UK winter. It supplies 5 micrograms and that advice names 10.
- We do not claim vitamin D does anything for vaginal or intimate health. No such claim exists for it, and we will not imply one by placing an unrelated claim next to intimate-health copy.
- We do not use the vitamin D claims relating to children, or the one concerning the risk of falling in older adults.
- We do not claim those seven sentences describe what this product does. They describe what the nutrient contributes to, assessed on the nutrient and not on our formulation.
- We do not claim this product treats, prevents or reduces the risk of anything.
What we claim is the composition: 5 micrograms of vitamin D3 as cholecalciferol, 100% of the Nutrient Reference Value.
Worth knowing
Vitamin D is fat-soluble, which means it accumulates rather than being cleared like the B vitamins, and it does have an upper intake level. 5 micrograms is a small fraction of it. If you already take a dedicated vitamin D supplement, a multivitamin or a cod liver oil, count ours alongside them. If you are pregnant, breastfeeding, have a condition affecting calcium, or take medication, speak to your GP or pharmacist before adding a supplement.
Common questions
- How much vitamin D is in Femme Flora?
- 5 micrograms of vitamin D3 per daily serving, equivalent to 200 IU, which is 100% of the Nutrient Reference Value. The threshold at which the health claims apply is 15% of the reference intake, so the dose clears it comfortably.
- Is 5 micrograms of vitamin D enough for the UK winter?
- Not on its own. NHS advice is that adults in the UK consider taking 10 micrograms a day between October and March, because British latitude does not allow enough production from sunlight. Ours supplies 5 micrograms and counts towards that total rather than replacing it.
- Why does the UK need vitamin D in winter?
- Between roughly October and March, sunlight at British latitudes does not carry enough UVB for skin to make vitamin D. It is the angle of the sun rather than the brightness of the day. Dietary sources are limited to oily fish, egg yolk and fortified foods.
- What is the difference between vitamin D3 and D2?
- D3 is cholecalciferol, the form skin makes from sunlight. D2 is ergocalciferol, produced by certain fungi. D3 is generally more effective at raising and maintaining blood levels, and it is the form we use in Femme Flora.
- Is your vitamin D3 suitable for vegans?
- Most commercial D3 comes from lanolin, which is derived from sheep wool and is not vegan; vegan D3 is made from lichen. Our manufacturer has confirmed in a written declaration, received 4 November 2026, that the D3 in Femme Flora is lichen-sourced.
Sources
- GB Nutrition and Health Claims Register. Checked against the register export of 19 May 2026. Seven general authorised claims for vitamin D, reproduced above verbatim. Three further claims exist and are not used: two relating to children, and one concerning reduction of the risk of falling associated with postural instability in men and women over 60. Condition of use: the food must be at least a source of vitamin D, meaning 15% of the Nutrient Reference Value per daily portion.
- Retained Commission Regulation (EU) No 432/2012, establishing the list of permitted health claims. The wordings above and the 15% NRV condition originate here.
- NHS guidance on vitamin D. Advice that adults in the UK consider a daily supplement containing 10 micrograms during autumn and winter, on the basis that UK sunlight is insufficient for skin synthesis in those months.