Last updated: October 2026
Take vitamin D with a meal that contains some fat, at whatever time of day you’ll remember it every day, because consistency matters more than the clock. Morning or evening both work. In the UK, the NHS says everyone should consider a daily 10 microgram (400 IU) supplement during autumn and winter.
Below: a quick guide, food and fat, morning vs night and sleep, D3 vs D2, K2, how much, sunlight in the UK, who should check first, and babies.
What to do: time, food, dose and form
| Question | What to do |
|---|---|
| Time of day | Any time you’ll stick to. Breakfast or your main meal suits most people |
| With food | With a meal that contains some fat, not on an empty stomach |
| Dose | 10 micrograms (400 IU) a day; no more than 100 micrograms (4,000 IU) unless a doctor advises it |
| Season | Autumn and winter; all year if you’re at higher risk |
| Form | Vitamin D3 in a format you’ll actually take. Algae or lichen D3 if you’re vegan |
| With K2 | Not needed for most people. Never take vitamin K supplements with warfarin |
For why winter matters, see our guide to vitamin D in winter.
Should you take vitamin D with food?
Yes. Vitamin D dissolves in fat, so a meal with some fat helps you absorb more. The NHS guide to colecalciferol (vitamin D3) says to take tablets and capsules with your main meal of the day. The studies:
- Fat vs no fat: in 50 healthy older adults given one large dose with breakfast, blood vitamin D3 peaked 32% higher after a meal containing fat than after a fat-free meal. The type of fat made no difference.
- How much fat: in a placebo-controlled trial of 64 young adults, levels rose more after two weeks when the dose came with a meal containing at least 15g of fat.
- Largest meal: in 17 bone clinic patients whose levels weren’t improving, taking their dose with their largest meal raised levels by about half over two to three months. It was small and had no comparison group.
You don’t need a fry-up: eggs, yoghurt, cheese, nuts, avocado, oily fish or olive oil all count. Oil-based drops already contain fat, but a meal is still a good habit.
Morning or night, and does it affect sleep?
There’s no good evidence that morning works better than night, or the other way round. Tie it to something you do daily, such as breakfast or your evening meal. Building a better start to the day? See our morning routine for energy.
Claims that vitamin D at night keeps you awake, or helps you sleep, rest on limited and mixed evidence:
- A 2021 review in healthy people found 11 observational studies on sleep with mixed results, and named supplement timing as an open question.
- A 2022 meta-analysis found vitamin D improved a sleep quality score in three small trials, with moderate certainty. Effects on sleep length and sleep disorders were unclear.
So there’s no clear reason to avoid an evening dose. If you feel it affects your sleep, move it to breakfast. For sleep itself, the basics matter more: see sleep hygiene and your circadian rhythm.
Vitamin D3 or D2?
Most supplements contain vitamin D3 (colecalciferol), the natural form of vitamin D in the body. Vitamin D2 (ergocalciferol) is the other main form.
A 2012 meta-analysis led by the University of Surrey found D3 raised blood levels more than D2. The difference was clear with large, infrequent doses but disappeared with daily doses. D3 is a sensible default, and a daily D2 product still gives you vitamin D.
Some D3 is animal-derived, and the NHS notes vitamin D capsules may contain gelatine. Vegan? Look for D3 from algae or lichen. See is CBD oil vegan?
Should you take vitamin D with K2?
There’s no NHS advice to take vitamin D with K2. The NHS says most people get all the vitamin K they need from a varied diet, such as green leafy vegetables, vegetable oils and cereal grains, and that 1mg or less a day from supplements is unlikely to cause harm.
Research on the pairing is limited. A 2024 review of 31 studies in postmenopausal women found the combination may have positive effects on bone and heart health markers, but trials varied a lot and the findings don’t apply to everyone.
Important: vitamin K affects blood clotting, and the NHS says not to take vitamin K supplements while on warfarin. If you take any blood thinner, ask your pharmacist first. Otherwise a D3 and K2 product is a personal choice, not a necessity.
Vitamin D with magnesium and other supplements
Magnesium and vitamin D can be taken together, and a 2018 review found the enzymes that activate vitamin D in the liver and kidneys appear to need magnesium. They don’t have to be taken at the same time. See magnesium and vitamin D together and the best time to take magnesium.
Count every product containing vitamin D, including multivitamins. If your doctor has prescribed vitamin D, the NHS says to check before taking other supplements containing calcium or vitamin D.
How much vitamin D to take
- Adults: 10 micrograms (400 IU) a day, which the NHS says is enough for most people.
- Upper limit: no more than 100 micrograms (4,000 IU) a day unless a doctor advises it, including in pregnancy, breastfeeding and for ages 11 to 17.
- Converting: 1 microgram = 40 IU, so 25 micrograms = 1,000 IU.
- All year: the NHS advises 10 micrograms daily all year if you’re rarely outdoors (for example frail or housebound), live in a care home, or usually cover most of your skin outdoors. If you have dark skin, for example an African, African-Caribbean or south Asian background, consider it all year too.
- If you’re deficient: a GP may prescribe a higher short-term dose after a blood test. Only take high doses on medical advice.
More in our vitamin D in winter guide. Think you might be low? See vitamin D deficiency symptoms and why you feel tired in winter.
Vitamin D from the sun in the UK
The NHS says that from about late March or early April to the end of September, most people can make all the vitamin D they need from sunlight on their skin. Between October and early March, the sun isn’t strong enough.
There’s no set time or number of minutes. The NHS advises striking a balance with sun safety:
- Never burn. You can burn in the UK, even when it’s cloudy.
- Spend time in the shade between 11am and 3pm from March to October, when the sun is strongest.
- At a UV index of 3 or more, consider protecting your skin with at least SPF30 and 4-star UVA protection.
Dark winter days take a toll in other ways too. See seasonal affective disorder, our winter wellness guide, how to boost your immune system and cold or flu?
Who should check with a GP or pharmacist first
The NHS advises telling your doctor before taking vitamin D (colecalciferol) if you have high calcium in your blood or pee, kidney problems or kidney stones, high vitamin D levels, sarcoidosis, or a peanut or soya allergy.
Some medicines interact with it, including digoxin, some diuretics (such as bendroflumethiazide and indapamide), epilepsy medicines, steroids such as prednisolone, cholestyramine and some antifungals. Ask your pharmacist if any apply.
Babies and children
- Breastfed babies should have 8.5 to 10 micrograms of vitamin D daily from birth, whether or not the mother takes it.
- Babies having more than 500ml (about a pint) of formula a day don’t need a supplement, as formula is fortified.
- Children aged 1 to 4 should have 10 micrograms every day, all year.
There’s no official best time for baby drops: give them at the same time each day and follow the label. If you qualify for Healthy Start, you can get free vitamin drops for children. Never give two vitamin D supplements at once.
Our products are for adults only, and we don’t recommend them during pregnancy or breastfeeding. The NHS advises pregnant and breastfeeding women to consider a separate 10 microgram vitamin D supplement.
Vitamin D3 in your CBD drops
For most people, a separate vitamin D supplement is the simplest way to get the NHS 10 micrograms. If you already use CBD oil, our Evolabs Mint CBD Oil adds vegan, algae-based vitamin D3 to broad spectrum CBD: 5 micrograms per half pipette, half the NHS figure. Count it towards your daily total. Read why we added algae-based D3 and when to take CBD oil.
Vitamin D contributes to the normal function of the immune system, the maintenance of normal bones and the maintenance of normal muscle function.
The FSA’s 10mg a day figure is precautionary advice rather than a legal limit, set while longer-term safety research continues. At Evopure we think it is a very cautious figure, and many adults use more. If you go above it, increase slowly, and check with your GP or pharmacist first if you take any medication.
See also can you take magnesium and calcium together?
See also our honest guide to vitamins for men over 40.
FAQs
Is it better to take vitamin D in the morning or at night?
Neither has been shown to work better. Take it at a time you’ll remember every day, with a meal that contains some fat. Many people find breakfast or their main meal easiest.
Should I take vitamin D before or after food?
With or just after food, ideally a meal containing some fat. Vitamin D is fat-soluble, and studies show it is absorbed better with a fat-containing meal than on an empty stomach.
Does taking vitamin D at night keep you awake?
There’s no good evidence that it does, and research on vitamin D and sleep is limited and mixed. If you feel an evening dose affects your sleep, take it in the morning instead.
Do I need to take vitamin D with K2?
No. There’s no NHS advice to add K2, and most people get enough vitamin K from a varied diet. Don’t take vitamin K supplements if you take warfarin.
Can I take vitamin D and magnesium together?
Yes. There’s no known harmful interaction at normal doses, and your body needs magnesium to activate vitamin D. They don’t have to be taken at the same time.
When should I start taking vitamin D in the UK?
From October, carrying on until about March. The NHS says everyone should consider 10 micrograms a day in autumn and winter, and some people all year.
Sources
- NHS. Vitamin D.
- NHS. How and when to take colecalciferol, who can and cannot take it and taking it with other medicines.
- NHS. Vitamin K and Warfarin.
- NHS. Vitamins for children and Sunscreen and sun safety.
- Uwitonze AM, Razzaque MS (2018). Role of magnesium in vitamin D activation and function. Journal of the American Osteopathic Association.
- Dawson-Hughes B et al (2015). Dietary fat increases vitamin D-3 absorption. Journal of the Academy of Nutrition and Dietetics.
- Raimundo FV et al (2015). Effect of fat on serum 25-hydroxyvitamin D levels after a single oral dose of vitamin D in young healthy adults. European Journal of Nutrition.
- Mulligan GB, Licata A (2010). Taking vitamin D with the largest meal improves absorption and results in higher serum levels of 25-hydroxyvitamin D. Journal of Bone and Mineral Research.
- Tripkovic L et al (2012). Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status. American Journal of Clinical Nutrition.
- Huiberts LM, Smolders KCHJ (2021). Effects of vitamin D on mood and sleep in the healthy population. Sleep Medicine Reviews.
- Abboud M (2022). Vitamin D supplementation and sleep: a systematic review and meta-analysis of intervention studies. Nutrients.
- Rusu ME et al (2024). Combined vitamin D and K supplementation in postmenopausal women: a review of clinical studies. Nutrients.
- FSA. Cannabidiol (CBD) guidance.
This guide is general information, not medical advice. Evopure makes the Evolabs Mint CBD Oil with vitamin D3.
