Can Vitamin D Be Taken On An Empty Stomach?

Answer

Thanks for reaching out! Whether or not a medication is recommended to be taken with food depends on a few factors.

Food can affect the absorption of some medications (either increase or decrease it, depending on the drug) and can sometimes help mitigate side effects, such as nausea and vomiting.

In regard to vitamin D, it can safely be taken on an empty stomach but a number of studies show that it is better absorbed if taken with a meal that contains at least some fat since it is a fat-soluble vitamin. It is unknown though whether or not this increase in absorption correlates to a clinical difference, over time, however.

Vitamin D Absorption: Better Absorption With A High Fat Meal

As mentioned, vitamin D can safely be taken on an empty stomach but it is generally recommended to be taken with a meal that contains fat as it will be better absorbed.

Nearly every study that has evaluated vitamin D absorption has noted that it is improved when taken with a fat-containing meal, anywhere from 20-60% better absorbed.

One such study concluded the following:

Thus it is concluded that taking vitamin D with the largest meal improves absorption and results in about a 50% increase in serum levels of 25(OH)D levels achieved. Similar increases were observed in a wide range of vitamin D doses taken for a variety of medical conditions.

Another study had a similar conclusion:

The presence of fat in a meal with which a vitamin D-3 supplement is taken significantly enhances absorption of the supplement, but the MUFA:PUFA [monounsaturated-to-polyunsaturated fatty acid ratio] of the fat in that meal does not influence its absorption

It should be noted that it is unknown if better absorption of vitamin D consistently correlates to higher levels in the blood over time. Some studies have found this to be the case, while others have not reliably found this relationship. One such study stated:

We conclude that absorption was increased when a 50,000 IU dose of vitamin D was taken with a low-fat meal, compared with a high-fat meal and no meal, but that the greater absorption did not result in higher plasma 25(OH)D levels in the low-fat meal group.

Differences in studies may be due to different dosing, administration schedules, and forms of vitamin D studied. More studies are needed for a more definitive conclusion.

Does Food Help Reduce Side Effects?

Another consideration with taking medication with food is whether or not it may help reduce the incidence and severity of certain side effects.

For example, many antibiotics are better tolerated when taken with food (i.e. less nausea). However, this doesn't seem to be an issue with vitamin D. Studies show it is very well tolerated, regardless of food intake. Nausea and other gastrointestinal-related problems generally aren't widely reported with vitamin D.

It should be noted that you can take too much vitamin D, so it is important to take it only as directed by your doctor.

Vitamin D Information

Vitamin D comes in several forms, including cholecalciferol (vitamin D3) and ergocalciferol. It is needed by the body for healthy bones, muscles, nerves, and to support the immune system.

Vitamin D works by helping the body to use more of the calcium found in foods or supplements. People most at risk for vitamin D deficiency are older adults, breastfed infants, people with dark skin, obese people, and those with limited sun exposure, or gastrointestinal diseases (GI; affecting the stomach or intestines) such as Crohn's disease or celiac disease.

Vitamin D is also used along with calcium to prevent and treat bone diseases such as rickets (softening and weakening of bones in children caused by lack of vitamin D), osteomalacia (softening and weakening of bones in adults caused by lack of vitamin D), and osteoporosis (a condition in which the bones become thin and weak and break easily). Cholecalciferol (vitamin D3) is in a class of medications called vitamin D analogs. 

Final Words

Thanks for your question! Reach back out anytime.