Though doses of up to 2,000 mcg of vitamin B12 are considered safe, it’s best to speak to a doctor to find out whether taking a supplement is necessary. Most people can fill their B12 needs through a healthy diet. Some, such as older adults or those with certain dietary restrictions, should supplement.
Early research suggests that taking twice the recommended daily allowance of vitamin B12, with or without folic acid, does not reduce the risk of diarrhea in children.
Adults (aged 19 to 64) need about 1.5 micrograms a day of vitamin B12. If you eat meat, fish or dairy foods, you should be able to get enough vitamin B12 from your diet.
A response usually is seen within 48 to 72 hours, with brisk production of new red blood cells. Once B12 reserves reach normal levels, injections of vitamin B12 will be needed every one to three months to prevent symptoms from returning.
You may need to take vitamin B-12 separately from the above drugs and supplements — say, one in the morning and one at night — so you can get the full dose of vitamin B-12. Don’t take vitamin B-12 supplements if you have sensitivities or allergies to vitamin B-12, cobalt, and any other ingredients.
Vitamin B-12, or cobalamin, is a nutrient you need for good health. It’s one of eight B vitamins that help the body convert the food you eat into glucose, which gives you energy. Vitamin B-12 has a number of additional functions.
In one 8-week study in 100 older adults, supplementing with 500 mcg of vitamin B12 were found to normalize B12 levels in 90% of participants. Higher doses of up to 1,000 mcg (1 mg ) may be necessary for some ( 10 ).
Summary: When you are deficient in B12, your body isn’t able to produce enough red blood cells to effectively transport oxygen throughout your body. This can make you feel tired and weak.
Certain medications can decrease the absorption of vitamin B12, including: colchicine, metformin, extended-release potassium products, antibiotics (such as gentamicin, neomycin, tobramycin), anti-seizure medications (such as phenobarbital, phenytoin, primidone), medications to treat heartburn (such as H2 blockers
Symptoms of Vitamin B12 Deficiency Weakness, tiredness, or lightheadedness. Heart palpitations and shortness of breath. Pale skin. A smooth tongue. Constipation, diarrhea, loss of appetite, or gas. Nerve problems like numbness or tingling, muscle weakness, and problems walking. Vision loss.
Common side effects pain, swelling or itchy skin where your injection was given. feeling or being sick (nausea or vomiting) diarrhoea. headaches.
B12 Causes Psychiatric Symptoms: B12 deficiency can cause almost any psychiatric symptom, from anxiety, and panic to depression and hallucinations. This is because B12 deficiencies trigger symptoms in the nervous system and red blood cells.
1. Jarrow Formulas’ Methyl B12: A previous favorite that’s held onto the top spot due to its special methylcobalamin formulation that’s easier to absorb than other types.