The Best Time of Day To Take Vitamin D

If you’re pregnant or have a vitamin D deficiency, you’ve likely been told to boost your vitamin D levels with the help of specific foods, supplements and more time in the sun. But does this “sunshine vitamin” have more benefits when you take it during the day? Or does it work better at night?

Rheumatologist Chad Deal, MD, explains when you should take vitamin D and why it’s important to take a food-first approach before starting a supplement.

When should you take vitamin D

There’s no single best time to take vitamin D. Some people prefer to take it in the morning. Others prefer to take it at night. Understanding how vitamin D works can help you decide when you should take it for the greatest benefit.

Vitamin D in the morning

Vitamin D is fat-soluble, which means your body needs fat and oil to dissolve it. You absorb vitamin D more easily when you take it with a full meal. As breakfast is so often the largest (and most important) meal of the day, the morning is a prime time to take the sunshine vitamin. Plus, vitamin D levels tend to be highest during the day because of our exposure to the sun. So, taking it in the morning sets you up for further success.

“Put your vitamin D bottle on the breakfast table as a sure way that you won’t forget to take the medication,” recommends Dr. Deal. “It’ll also help make sure you take it with a meal.”

Vitamin D in the evening

Some may prefer to take it in the evening, but research is mixed on its effectiveness. A 2021 review found that taking vitamin D in the evening may result in a lower production of melatonin (a hormone that helps you fall asleep and regulates your sleep-wake cycle). Other studies suggest it can improve sleep. More research is needed to know the exact effects vitamin D has when it’s taken later in the day.

“People often take their nighttime meds before getting in bed instead of taking them with a meal,” notes Dr. Deal. “This might limit the absorption of vitamin D.”

Factors to consider

How well vitamin D supplements work (and how much you need) depends on the following factors:

• Your age: Older adults may have more difficulty absorbing vitamin D. They’re also not as efficient at converting sunlight into vitamin D. This can lead to an increase in vitamin D deficiency.
• Your location: Your vitamin D levels will decrease if you have limited sun exposure because you work the night shift or live in an area with less sunlight.
• Your skin color: People with darker skin tones have more difficulty converting UV (ultraviolet) rays into vitamin D. Their skin tends to have more amounts of melanin (which gives skin pigmentation), which blocks this process.
• Mealtimes: Vitamin D is best used when taken with a meal or snack that contains healthy fats, like olives, walnuts or brown rice. It’s also found in natural and fortified foods, like salmon and breakfast cereal.
• Other medications and supplements: Some medications, like antacids and diuretics, can interact poorly with vitamin D.

Ultimately, it’s up to you and your healthcare provider to decide when you should take vitamin D. They can guide you based on your health status, medications and any underlying conditions you may have.

And it’s always best to speak with a doctor before taking any supplement, as too much vitamin D can be toxic.