Two studies used 1000 μg/day oral vitamin B12 and showed no relevant difference to intramuscularly applied vitamin B12 with regard to vitamin B12 blood levels. One trial used 2000 μg/day vitamin B12 and showed higher vitamin B12 blood levels in favour of oral vitamin B12.
High doses of oral vitamin B12 (e.g. 1000 µg daily) may be able to produce adequate absorption of vitamin B12 even in the presence of intrinsic factor deficiency, and therefore may be an alternative to the intramuscular route for many people.
To absorb more B12, divide the dose over the course of the day and take separately from a B12-containing meal. If you take a higher dose, such as 100 mcg, you will absorb only about 1% of the amount above 2.4 mcg -- although this may be appropriate in some situations.
Your body can't absorb all the vitamin B-12 from dietary supplements. Absorption is limited by how much intrinsic factor your stomach makes. Intrinsic factor is needed for your body to absorb B-12. For example, only about 10 mcg of a 500 mcg oral supplement is actually absorbed in healthy people.
It's usually best to take the tablets on an empty stomach. This means at least 2 hours after a meal or snack and at least 30 minutes before you eat again.
Vitamin B12
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.
Some stomach conditions or stomach operations can prevent the absorption of enough vitamin B12. For example, a gastrectomy, a surgical procedure where part of your stomach is removed, increases your risk of developing a vitamin B12 deficiency.
For example, absorption is only about 2% at doses of 500 mcg and 1.3% at doses of 1,000 mcg [24]. In addition to oral dietary supplements, vitamin B12 is available in sublingual preparations as tablets or lozenges [22]. Evidence suggests no difference in efficacy between oral and sublingual forms [25,26].
You need intrinsic factor so that your body can absorb B12 vitamin. People with pernicious anemia have a B12 vitamin deficiency.
Typically, our patients experience positive effects between 24-72 hours after the treatment.
Vitamin B12 is attached to protein molecules in food and can only be absorbed by the body after being split from the protein by hydrochloric acid in the stomach.
One study used a daily oral dosage of 2,000 mcg, and the other an oral dosage of 1,000 mcg daily for 10 days, then weekly for four weeks, then monthly for life. In both studies, high-dose oral B12 was as effective as intramuscular injection at achieving neurologic and hematologic response.
When taken at appropriate doses, vitamin B-12 supplements are generally considered safe. While the recommended daily amount of vitamin B-12 for adults is 2.4 micrograms, higher doses have been found to be safe. Your body absorbs only as much as it needs, and any excess passes through your urine.
Once you begin treating your vitamin B12 deficiency, it can take up to six to 12 months to fully recover. It is also common to not experience any improvement during the first few months of treatment. If you can, it's a good idea to address what's causing the deficiency.
Fatigue. Megaloblastic anemia due to vitamin B-12 deficiency may lead to a person feeling fatigued. Without enough red blood cells to carry oxygen around their body, a person can feel extremely tired.
Even the lowest doses in B12 supplements are many times the recommended dietary allowance. Doses up to 1,000 mcg, though unnecessary, aren't harmful.
Furthermore, caffeine interferes with the metabolism of certain B vitamins, including thiamine. However, because caffeine increases stomach acid secretion, it actually boosts the absorption of vitamin B12.
Apples Aside from being an important inclusion in a list of vitamin B12 fruits, apples are also rich in fibre, antioxidants, and flavonoids. Apples also comprise polyphenols that are found in both the peel and the pulp of the nutrient-dense fruit.
Vitamin B12 is considered an important brain and nervous system micronutrient and is often used for anxiety. It helps to ensure normal function for your nerves, which can help combat physical symptoms of anxiety.
Vitamin B12 deficiency can have distressing neuropsychiatric symptoms. It can have an etiological role in clinical presentations like depression, anxiety, psychosis, dementia, and delirium, requiring screening of at-risk populations.
Can You Take Vitamin B12 on an Empty Stomach? Vitamin B12 is water-soluble, which means you can take it with or without food. (Water-soluble vitamins don't require fat content to aid absorption.) If you have a sensitive stomach, however, we do recommend taking supplements with food.