Since vitamin D is a fat-soluble vitamin—meaning it doesn't dissolve in water—your body can most easily absorb it when you take it with food. On top of that, many people find that taking vitamins and supplements on an empty stomach can lead to side effects like gastric upset.
Since vitamin D is fat soluble, it's best not to take it on an empty stomach. For maximum absorption, take it with a substantial meal, and preferably one that includes fat-containing foods like nuts, seeds, and eggs.
Vitamins and nausea
“Taking vitamins on an empty stomach can frequently upset the GI tract,” says gastroenterologist Christine Lee, MD. “Many people experience stomach pains, nausea and even diarrhea.”
Vitamin D is a fat-soluble vitamin, meaning that it does not dissolve in water and is absorbed best in your bloodstream when paired with high fat foods ( 1 ). For this reason, it's recommended to take vitamin D supplements with a meal to enhance absorption.
Vitamin D supplements can be taken with or without food and the full amount can be taken at one time. While your body needs vitamin D to absorb calcium, you do not need to take vitamin D at the same time as a calcium supplement.
Taking vitamin D with the largest meal improves absorption and results in higher serum levels of 25-hydroxyvitamin D.
The health of your gut.
Therefore, conditions that affect the gut and digestion, like celiac disease, chronic pancreatitis, Crohn's disease, and cystic fibrosis, can reduce vitamin D absorption.
If you take large doses of vitamin D, you may experience stomach pain, loss of appetite, constipation, or diarrhea as a result of elevated calcium levels.
How to use Vitamin D3. Take vitamin D by mouth as directed. Vitamin D is best absorbed when taken after a meal but may be taken with or without food.
The main consequence of vitamin D toxicity is a buildup of calcium in your blood (hypercalcemia), which can cause nausea and vomiting, weakness, and frequent urination. Vitamin D toxicity might progress to bone pain and kidney problems, such as the formation of calcium stones.
Vitamins that are more acidic in nature ― like vitamin C or folate ― may cause nausea if they're consumed on an empty stomach, Poppers told HuffPost.
Iron, magnesium and fish oil supplements are the most common culprits for digestive upset when taken on an empty stomach, so take extra care to have these with a meal or snack.
You'll be sleepy the next day. Several studies even saw a dose-dependent relationship between vitamin D levels and sleep. [1,2] This adds to the evidence that there is a direct, linear relationship between vitamin D and sleep measures. This also means that improving your vitamin D by any amount will improve your sleep.
Growing evidence has demonstrated that vitamin D has a role in sleep regulation [12]. Specifically, vitamin D deficiency (VDD) can increase risk of sleep disorders and is associated with sleep difficulties, shorter sleep duration, and nocturnal awakenings in children and adults [13,14,15].
There's no set time of day that's best to take vitamin D supplements. Some people say taking vitamin D supplements at night is an insomnia risk. There's no research to confirm this, but you might want to take your supplement earlier in the day if you think it's screwing with your sleep.
Too much or too little of necessary nutrients, such as vitamin D, can cause significant health problems. That being said, when you intake excess or toxic levels of vitamin D, you may experience constipation, in addition to other digestive problems, loss of appetite, and muscle weakness.
If you're not getting enough vitamin D, a vitamin D deficiency could be the cause of gas and gas-related bloating. In fact, one study showed that people who increased their levels of vitamin D had fewer gastrointestinal issues overall.
Usually, vitamin D toxicity results from taking excessive amounts. In vitamin D toxicity, resorption of bone and intestinal absorption of calcium is increased, resulting in hypercalcemia. Principal causes include hyperparathyroidism... read more .
Magnesium assists in the activation of vitamin D, which helps regulate calcium and phosphate homeostasis to influence the growth and maintenance of bones. All of the enzymes that metabolize vitamin D seem to require magnesium, which acts as a cofactor in the enzymatic reactions in the liver and kidneys.
Official answer. Generally, it takes a few weeks of taking daily vitamin D supplements for vitamin D levels in the body to rise. Each 1,000 IU of vitamin D3 taken daily is expected to raise blood levels of 25(OD)D by 10 ng/ml after a few weeks.
Research also demonstrated that the higher the level of caffeine, the more it interfered with vitamin D absorption. The study suggested that caffeine did this by reducing the expression of vitamin D receptors on osteoblasts in the body – the cells responsible for producing bone.
Muscle weakness due to vitamin D deficiency is predominantly of the proximal muscle groups and is manifested by a feeling of heaviness in the legs, tiring easily, and difficulty in mounting stairs and rising from a chair; the deficiency is reversible with supplementation (15–18).
There are quite a few differences between vitamin D and vitamin D3, but the main difference between them is that vitamin D is a fat-soluble vitamin that regulates calcium and phosphorous levels in the body, whereas the vitamin D3 is the natural form of vitamin D produced by the body from sunlight.