Can I Take Vitamin D at Night?
Many people are unsure when the best time is to take vitamin D. Some also wonder if taking their supplement at night might help with better sleep. The good news is that getting enough vitamin D can improve sleep quality, though the time of the day you take it might not be as important as just making sure you’re getting enough since many of us don’t even get enough sun exposure to provide adequate amounts of vitamin D.
Does Timing Matter for Vitamin D?
Vitamin D is fat-soluble, meaning it has better absorption with a meal that includes fat.1 In order to get the most health benefits, it’s important to consider when and how you take vitamin D—not just whether.
Mealtime Supports Better Vitamin D Absorption
Research consistently shows that taking vitamin D with a meal full of healthy fats—like eggs, avocado or salmon—can boost blood levels of the nutrient, especially for those with a vitamin D deficiency:
- In one trial, people who paired vitamin D in a variety of doses with their largest meal raised their blood levels by about 50% over two to three months.2
- Another study in older adults found a 32% increase in vitamin D levels just 12 hours after taking a dose of 50,000 IU with a high-fat meal, compared to a fat-free one.3
Morning vs. Evening—What Science Says
Experts at the Cleveland Clinic confirm there’s no “one best time” to take vitamin D—as long as you pair it with food.4
Some early studies suggested that taking very high doses of vitamin D late in the day might interfere with production of melatonin, which could affect the sleep wake-cycle.5 But a range of researching studies supplementing 1,000 - 7,500 IU per day of vitamin D3 demonstrate that it may improve sleep.6,7 For most people, timing comes down to consistency and comfort.
What Happens if You Take Vitamin D at Night?
You probably won’t have any issues taking vitamin D before bedtime as long as you have it with food, although it’s generally considered a better idea to take vitamin supplements earlier in the day.
If you’re sensitive to sleep changes, the simplest fix is to take vitamin D with your evening meal instead of right at bedtime. That still gives you good absorption without potential melatonin disruption.
One meta-analysis showed supplementation improved sleep quality overall.6 Another found higher vitamin D levels were linked to longer sleep duration in adults.8 Neither specified timing of administering vitamin D as playing a demonstrable effect, however.
How Much Vitamin D Do You Need?
Figuring out the right amount of vitamin D can be tricky since everyone’s needs and health conditions are different. That’s why it’s always important to speak with your doctor or healthcare provider before starting any new supplements.
In general, however, the National Institutes of Health recommends 600 IU daily for people under 70, and 800 IU daily for those 70 and older.1 Serum vitamin D responds to supplements slowly—around 5 nmol/L (2 ng/mL) increase per 100 IU taken daily, averaging over weeks to months.9 Higher doses can raise blood serum levels faster.
High doses, like 5,000 IU/day, can be safe under a doctor’s or healthcare professional’s supervision. It’s best to continue testing to guide your vitamin D intake and ensure your blood levels stay within a healthy range.
Easy Routine for Consistent Use
Here’s a helpful habit to build:
- Pick a meal: morning breakfast, afternoon lunch or evening dinner.
- Take your vitamin D supplement with your chosen meal (featuring healthy fats).
- Keep it simple—having it with the same meal each day helps you remember to take your supplement.
Ideal examples:
- Breakfast with eggs and avocado or full-fat yogurt.
- Dinner alongside salmon, olive oil or cheese.
Do You Ever Need to Switch Up the Timing?
If your schedule changes, for example during travel times, just stick with whichever meal of the day is easiest. The key is taking it with fat and making it part of your daily routine.
You be well, now.
Swanson
*These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.
Sources
1. Vitamin D Fact Sheet for Health Professionals. NIH Office of Dietary Supplements, 2025. Read source
2. Mulligan GB, Licata A. J Bone Miner Res. 2010 Apr;25(4):928-30. Read source
3. Dawson-Hughes, B et al., Journal of the Academy of Nutrition and Dietetics; 2015/02/01. 115(2); 225-230. Read source
4. The Best Time of Day To Take Vitamin D, Cleveland Clinic, June 17, 2025. Read source
5. Romano F, et al. Curr Pharm Des; 26(21). 2020. Read source
6. Abboud M. Nutrients. 2022 Mar 3;14(5):1076. Read source
7. Huang, G, et al. Frontiers in Nutrition, July 21, 2022. Read source
8. Larsen, L.A. et al., Sleep Medicine: X (4); 2022, 100056. Read source
9. Ramasamy I. Clin Biochem Rev. 2020 Dec;41(3):103-126. Read source
