Fat-soluble and water-soluble vitamins Some combinations should be avoided, even if they aren't inherently problematic. For example, although it's safe to take vitamin D with vitamin B12, it's not advisable, says Virgilio Sanchez, MD, a board certified family medicine physician at Conviva Care Center in Miami, Florida.
According to health experts at Click Pharmacy, as a general rule of thumb, take your B vitamins in the morning or with a meal. Vitamin B12, for example, should definitely be taken in the morning. This is because it is important for energy metabolism, which may interrupt your sleep if taken at night.
Taking vitamin B-12 with vitamin C might reduce the available amount of vitamin B-12 in your body. To avoid this interaction, take vitamin C two or more hours after taking a vitamin B-12 supplement.
Some studies suggest that the body may not be able to absorb vitamin K as efficiently when taken with vitamins D and E. As a result, taking a large dose of these three vitamins together may prevent vitamin K from clotting the blood effectively [7].
According to Coutinho, long term use of antacids and other medications, heavy treatments like chemotherapy, poor gut health, chronic stress, low stomach acids, fad diets and going completely fat-free can lead to such deficiencies. Having Crohn's or kidney disease may also inhibit vitamin D and B12 absorption.
Increasing one's intake of vitamin D without enough vitamin K can cause an increase in calcium levels without the ability to use it effectively, which raises the risk of depositing calcium in arteries and soft tissue. This is dangerous because it can lead to heart disease, heart attack and even stroke.
Vitamin D and calcium are an important combo. Both are essential for the health of your bones. While some suggest that vitamin D on its own can support bone health, most studies examine its effect when paired with calcium.
Taking vitamin B12 with vitamin C may lower the amount of B12 available in your intestine. To avoid this interaction, wait 2-3 hours to take vitamin C after your B12 supplement.
Other medications can also interfere with your uptake of vitamin B12, possibly raising your risk for deficiency. These medications include antacids and peptic ulcer medications, cholesterol-lowering drugs, antiseizure medications, chemotherapy medications, the diabetes treatment glucophage (Metformin) and others.
Having a digestive system disorder: Digestive disorders such as celiac disease and Crohn's disease can make it more difficult for your body to absorb vitamin B12. Following a strict vegan or vegetarian diet: Vitamin B12 is only naturally found in animal products such as meat and dairy.
B12 (also known as cobalamin) is essential for keeping your brain and nerves healthy and for making DNA and red blood cells. B12 also helps lower levels of homocysteine, an amino acid linked (in high levels) to dementia, heart disease, stroke, and osteoporosis.
tl;dr. 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.
When to take vitamin D. It just plain doesn't matter, as long as you take it with food, says Dr. Manson. Her advice: Take it when you'll remember to take it — morning, noon or night — and take it with a meal, she says.
The best time to take fat-soluble vitamins like vitamin D, A, and K is with a meal containing fats. You should take water-soluble vitamins like vitamin C, B12, and B6 in the morning on an empty stomach. Take multivitamins or prenatal vitamins with a meal or snack containing fat and a glass of water.
Vitamins B12, B6, and B9 work together to control blood levels of the amino acid homocysteine. High levels of homocysteine are associated with heart disease.
Some vitamins that should not be taken together, or have dosage limitations, include vitamin C with vitamin B-12, vitamin A supplement with vitamin A-rich foods, folic acid (vitamin B9) and vitamin B12, and vitamin E with vitamin K.
Our only hard recommendation: Avoid supplementing with vitamin D at night. There's evidence that vitamin D can suppress melatonin—which is bad news for your sleep quality.
If you take too much supplemental or prescription vitamin D, it can lead to vitamin D toxicity. The main complication of this is moderate to severe hypercalcemia, which can cause symptoms like vomiting, increased thirst and frequent urination.
Stage 1 is decreased levels of vitamin B12 in the blood. Stage 2 is low concentration of vitamin B12 in the cell and metabolic abnormalities. Stage 3 is increased levels of homocysteine and MMA and decreased DNA synthesis resulting in neuropsychiatric symptoms. Stage 4 is macrocytic anemia.
You may feel tired and weak. High amounts of vitamin B12 can also cause you to feel like your hands and feet are tingling. Some studies suggest that taking 25 mcg or more per day might increase your risk of bone fractures. Vitamin B12 injections should only be used to treat severe deficiencies.