Vitamin D Guide
Ingredient guide
Vitamin D3 + K2, without the guesswork.
Understand D3, K2, serving strength, UK guidance, and medicine cautions before choosing a daily supplement.
Quick Answer
Vitamin D is one of the few supplements with clear UK public-health guidance: adults and children over 4 should consider a daily 10mcg supplement during autumn and winter because sunlight is weaker and food alone can be difficult.
Root & Pulse Vitamin D3 + K2 is a more focused adult product, not a basic 10mcg winter supplement. Use this kind of formula only after checking your current routine, total vitamin D intake, and whether vitamin K2 is suitable for you.
Why Vitamin D Matters
Vitamin D helps the body regulate calcium and phosphate. In Great Britain, authorised claims for vitamin D include contribution to the maintenance of normal bones, normal muscle function, normal teeth, and normal immune system function when the product meets the conditions of use.
Most people can make vitamin D from sunlight between late March or early April and the end of September. During autumn and winter, UK guidance says people need to rely more on diet and supplements.
Dose Context
The key number on a vitamin D label is the microgram amount. Vitamin D may also be shown in IU: 1mcg equals 40 IU, so 10mcg equals 400 IU and 75mcg equals 3000 IU.
| Label point | What it means | Good question |
|---|---|---|
| 10mcg / 400 IU | The common UK public-health supplement amount for adults and children over 4 in autumn and winter. | Do you simply need a basic seasonal vitamin D routine? |
| 75mcg / 3000 IU | The vitamin D3 amount in Root & Pulse Vitamin D3 + K2 per capsule. | Have you checked other supplements and whether this strength suits you? |
| 100mcg / 4000 IU | The NHS adult daily upper limit unless a doctor advises otherwise. | Would this product plus your existing routine take you too close to the limit? |
| Vitamin K2 MK7 | A paired vitamin K form used in some D3 + K2 products. | Do you take warfarin or another medicine where vitamin K needs professional advice? |
D3 And K2 Compared
D3 is cholecalciferol, a form of vitamin D. K2 is a form of vitamin K; MK7 is a common label term for menaquinone-7. These are different nutrients, so a D3 + K2 product should be judged by both amounts, not only the vitamin D number.
| Nutrient | Authorised claim context | Label check |
|---|---|---|
| Vitamin D | Contributes to normal bones, teeth, muscle function, immune system function, and calcium absorption when conditions are met. | Check the microgram amount and the total from all supplements. |
| Vitamin K | Contributes to normal blood clotting and the maintenance of normal bones when conditions are met. | Check suitability if you take anticoagulant medication, especially warfarin. |
| D3 + K2 pairing | A focused format for people who specifically want both nutrients in one capsule. | Check whether a simpler vitamin D-only product would be enough. |
How To Choose
1. Start with why you are taking it
If your aim is the standard UK autumn and winter routine, a 10mcg vitamin D supplement may be enough for many people. A higher-strength D3 + K2 formula is a more deliberate choice.
2. Add up every vitamin D source
Multivitamins, immunity formulas, bone products and some women's wellness products can already contain vitamin D. Check every label before adding another vitamin D product.
3. Check whether K2 fits your medicines
NHS advice says people taking warfarin should not take vitamin K supplements unless advised. If you take anticoagulants, ask your GP, anticoagulant clinic or pharmacist before starting a D3 + K2 product.
4. Choose a routine you can repeat
Vitamin D is often taken daily. A one-capsule format is simple, but the best routine is the one that fits your food, medicines, and advice from a qualified professional.
Safety And Suitability
Taking too much vitamin D over a long period can cause too much calcium to build up in the body. NHS advice says adults should not take more than 100mcg or 4000 IU of vitamin D a day unless following medical advice.
Root & Pulse Vitamin D3 + K2 is positioned for adults. It is not recommended for children, pregnant or breastfeeding women. Speak with a qualified professional if you take medication, are under medical supervision, or manage a health condition.
Common Questions
Is 3000 IU the same as 75mcg vitamin D?
Yes. Vitamin D may be shown in micrograms or IU. 1mcg equals 40 IU, so 75mcg equals 3000 IU.
Does everyone need a D3 + K2 supplement?
No. Many people looking for basic seasonal vitamin D may only need to consider a 10mcg vitamin D supplement during autumn and winter. D3 + K2 is a more focused choice.
Can I take Vitamin D3 + K2 with a multivitamin?
Check the multivitamin label first. Many multivitamins already include vitamin D or vitamin K, so you need to add up your total daily intake before stacking products.
Should I take Vitamin D3 + K2 if I use warfarin?
Do not start vitamin K supplements while taking warfarin unless your doctor, anticoagulant clinic or pharmacist says it is suitable for you.
References
- Vitamin D, NHS vitamins and minerals guidance.
- Vitamin D supplementation during winter: PHE and NICE statement, GOV.UK.
- Great Britain nutrition and health claims register, Department of Health and Social Care, updated 19 May 2026.
- Vitamin K, NHS vitamins and minerals guidance.
- Warfarin, NHS medicine guidance.
- Nutrition, health claims and supplement labelling, GOV.UK food labelling guidance.
Root & Pulse educational content is for general information only and is not medical advice. Always read product labels and speak with a qualified professional if you are pregnant, breastfeeding, taking medication, or managing a health condition.