The best time to take vitamin D is at any time you can take it consistently, preferably with a meal that includes a good source of healthy fats for optimal absorption.
No significant research studies support the notion that any specific time of day is better than another for taking vitamin D supplements.
Taking vitamin D with a meal containing fats is more important than the time of day, as it is a fat-soluble vitamin and requires fats to be absorbed properly through the bloodstream.
This means that supplement timing should likely be around meals. Most people find that breakfast works best as it’s easy to get into a routine of taking it consistently around the same time of day, but any meal would work.
You can take vitamin D supplements with a snack that contains healthy fats as well, such as a handful of nuts, peanut butter, avocado, or olive oil.
Why Vitamin D Absorption Depends on Timing
Vitamin D is a fat-soluble vitamin, which means it requires dietary fat to help with absorption. This is true whether you are consuming a food source of vitamin D, such as fatty fish, beef liver, egg yolks, dairy products, or mushrooms, or a dietary supplement.
Food sources sometimes contain fats already or are combined with fats in a meal or snack, which makes it less talked about. Whereas with supplements, this isn’t always common.
Even the presence of a small amount of fat is preferred over none. Vitamin D will dissolve in fat and then be more easily transported into the bloodstream and to the gut for absorption.
While taking your vitamin D supplement on an empty stomach won’t result in health concerns, it won’t allow much absorption from that supplement. If you are taking vitamin D, you likely need it, so you want to get the most out of it.
Research suggests that taking vitamin D supplements, with a meal containing fat, can increase the bioavailability of that supplement by over 30% [1].
Like any dietary supplement, consistency is what is most important. Establishing a regular time of day you take your supplement can ensure you are getting the most out of it. You don’t need to be exact down to the minute, as long as you are consistent in taking it daily.
Morning vs Night: Does It Really Matter?
There is currently no medically established time of day that is preferred when taking vitamin D supplements. However, there are some considerations for when it might be more helpful to take it.
When comparing mornings versus nights, typically nighttime is not a preferred time to take vitamin D supplements, as it has the potential to interfere with sleep.
Vitamin D supplements taken at night might affect melatonin production, which regulates your sleep-wake cycle. This is more likely to occur in those taking high doses of vitamin D.
Your body associates vitamin D with sunlight, as this is your body’s primary source of vitamin D. Your body associates melatonin with nighttime, preparing your body for sleep.
Some studies suggest that high doses of vitamin D taken at night might decrease melatonin production and disrupt your circadian rhythm, leading to sleep alterations. While studies on this are limited, it’s an important consideration, especially for those who already struggle with sleep [2, 3].
Alternatively, taking vitamin D supplements in the morning might help support a healthy circadian rhythm. Those who are low in vitamin D are also more likely to suffer overall from sleep conditions [4].
However, if you are someone who doesn’t eat breakfast, typically has lunch out of the home, dinner may be the best meal for you to take your vitamin D with.
At the end of the day, it depends on your schedule. Best advice: do what fits your routine with food. Choose a time you are most consistent with eating a meal, ideally at home, where you can get into a habit of taking your supplement with it.
Should You Take Vitamin D With or Without Food?
Taking vitamin D with food is preferred, as it helps to increase absorption, so you get more out of your supplement. However, you do still absorb some vitamin D if taken on an empty stomach, or with a meal that doesn’t contain any fat; you just get much less.
It’s easiest to take vitamin D supplements with a meal, as they are more likely to contain some fat to help with the absorption. Even a small amount of dietary fat can help.
There is no hard and fast rule as to how much fat must be present at a meal for optimal absorption, but it is recommended to focus on healthy fats such as whole eggs, nuts, avocado, olive oil, and fatty fish for overall health.
Research studies show that moderate amounts of fat, about 11 grams, might be more favorable for vitamin D absorption compared to no fat or high-fat amounts. This equates to about a tablespoon of butter [1, 5].
However, the amount of fat consumed during meals to support stable vitamin D levels is likely less important than regular intake of the vitamin itself. This brings it back to consistency in taking your vitamin D supplement regularly.
What If You Take Vitamin D on an Empty Stomach?
If you do take vitamin D on an empty stomach, it’s not the end of the world. While not ideal, it’s not exactly harmful.
Like other vitamins, when taken on an empty stomach, there is a chance of side effects. These are typically limited to digestive discomfort, nausea, diarrhea, or stomach cramps.
If you are taking vitamin D to improve a deficiency, it will likely take longer to resolve due to suboptimal absorption. It could end up being more costly depending on the price of the supplement and why you are taking it.
Without the presence of fat, a large portion of supplemental vitamin D may go through your digestive tract unused.
While it might be more convenient for some to take it at different times of the day on an empty stomach, even including a small snack with it can make a difference over going without.
Special Considerations for Supplement Timing
Certain digestive conditions can impact your body’s ability to absorb vitamin D, specifically in conditions like celiac disease and irritable bowel disease.
During the initial diagnosis of these and other digestive conditions that can impair absorption, high amounts of vitamin D may be prescribed for repletion.
In these populations, the same rule applies and may be even more important to follow: be consistent with supplementation and take it with a meal containing fat. This tends to work best for breakfast or lunch.
Because these conditions often require high-repletion of vitamin D, it’s best to avoid taking vitamin D in the evenings if any sleep challenges exist.
Be mindful if you are taking other dietary supplements. Make sure to disclose your supplements to your healthcare provider to ensure none interact with each other.
Don’t take vitamin D supplements with calcium, magnesium, or phosphorus unless recommended by your healthcare provider, as these combinations can increase the risk of adverse health effects or toxicity.
Vitamin D supplements can interact with several medications, including diuretics, corticosteroids, statins, certain cholesterol-lowering drugs, and others [6].
Interactions can include impairing the effectiveness of the medication itself or depleting vitamin D levels.
For example, high doses of vitamin D may make statin drugs less effective. Other cholesterol-lowering drugs and corticosteroids can reduce the amount of vitamin D the body absorbs, which can affect bone density and increase fracture risk.
Additionally, certain diuretics can increase the risk of excessive calcium levels when combined with vitamin D.
If you are taking other supplements or medications, consider adjusting the timing you take them to avoid competition or interference. Always disclose your supplements to your healthcare provider so they can make adjustments based on your needs.
How Much Vitamin D Do You Really Need?
The Recommended Daily Allowance (RDA) for vitamin D varies by age. For adults 19-70 years old, it’s recommended to get 600 IU or 15 mcg of vitamin D daily. Those who are over 70 require higher amounts of 800 IU or 20 mcg daily [7].
You should have your vitamin D levels tested by your healthcare provider, especially if you are at a higher risk of low vitamin D.
The recommended vitamin D levels in your blood range anywhere from 20-50ng/mL. A vitamin D deficiency is present if levels fall below 20ng/mL. Many healthcare providers may encourage a vitamin D supplement if your levels are between 20-30ng/mL, as this is considered insufficient [8].
If your vitamin D levels are insufficient or a deficiency is present, supplementation is necessary. Vitamin D supplements are available over-the-counter as either vitamin D2 or D3. High doses can also be prescribed.
Both D2 and D3 can help increase serum vitamin D levels; however, vitamin D3 is preferred as it helps raise levels more efficiently [8].
If a deficiency is present, healthcare providers will typically prescribe a high-dose vitamin D supplement short term to help correct vitamin D levels, followed by a maintenance dose. Supplement dosage depends on the severity of the deficiency as well as individual factors.
For adults under 65, supplements of 400 to 800 IU are recommended to help prevent a deficiency. Those who are 65 and older should take 800 to 1,000 IU. Vitamin D supplements should not exceed 4,000 IU if a deficiency is not present [9].
Those who are being treated for a deficiency may require initial doses of up to 10,000 IU and maintenance doses of 3,000 to 6,000 IU daily [9].
Factors that can affect your vitamin D levels include skin tone, level of sun exposure, BMI, age, certain medications, and the presence of malabsorption disorders. Always consult your doctor before taking a vitamin D supplement, especially for high doses.
Final Thoughts – Timing Matters, But Consistency Wins
Timing your vitamin D supplement is important, especially when it comes to remembering to take it and having it with food. But, at the end of the day, the most important thing is that you take it consistently.
Keep timing in mind to help ensure you get the most out of your vitamin D supplement. Choose a consistent time you are likely to remember and will be having a meal. Get into a routine and stick to it daily.
FAQ Section
Is it better to take vitamin D in the morning or at night?
It’s best to take vitamin D at whatever time works for you to take it consistently. However, if you have challenges with sleep and are taking a high-dose vitamin D supplement, morning or early afternoon may be best to avoid any sleep disruptions.
Does vitamin D affect sleep?
Some research studies high doses of vitamin D taken at night have the potential to interfere with sleep, as it can reduce melatonin production. While research on this is not strong, it’s best to avoid taking vitamin D at night if sleep challenges are already present.
Should I take vitamin D with coffee or tea?
Caffeine can interfere with the absorption of vitamin D. If you are consuming coffee or caffeinated teas, such as green or black teas, it’s best to wait at least an hour before taking your vitamin D.
Can I combine vitamin D with magnesium or omega-3?
You can combine vitamin D with magnesium as they both work together to support bone health. However, those with existing kidney conditions should avoid taking vitamin D and magnesium together, as it can lead to dangerously high levels of magnesium in the bloodstream.
Taking vitamin D and omega-3s is also okay and may even improve the absorption of vitamin D.
