High sources of Vitamin B12, Foods rich in Vitamin B12, Vitamin B12 deficiency symptoms

Definition

Vitamin B12 is an essential water-soluble vitamin. There are several forms of vitamin B12 that contain the mineral cobalt. Another name for vitamin B12 is cobalamins. Two types active in humans are methylcobalamin and 5-deoxyadenosylcobalamin. Vitamin B12 is bound to protein in animal foods. Vitamin B12 is released in the stomach by gastric protease and hydrochloric acid. Synthetic vitamin B12 in dietary supplements is in its free form and does not require separation. Free vitamin B12 combines with intrinsic factors in the stomach and absorbed from the small intestine into the bloodstream. About 55% of a 1 microgram oral dose is absorbed. Absorption depends on the availability of intrinsic factors. The amount of vitamin B12 absorption also depends on other factors like the use of protein pump inhibitors for acid reflux and heartburn. 

Reasons why vitamin B12 is an essential vitamin 

Essential vitamins are vitamins your body can't make that must come from your diet. Vitamins that are water-soluble are not stored in your body. So, your diet must provide enough Vitamin B12 daily. Vitamin B12 is required for -

• DNA synthesis 
• red blood cell formation 
• converting homocysteine to methionine
• neurological functions

Vitamin B12 US-RDA

The current USA Recommended Dietary Allowance (RDA) or Daily Value for vitamin B12 according to the National Institutes of Health varies with age.

Age	Male	Female
0-6 months	0.4 mcg	0.4 mcg
7-12 months	0.5 mcg	0.5 mcg
1-3 years	0.9 mcg	0.9 mcg
4-8 years	1.2 mcg	1.2 mcg
9-13 years	1.8 mcg	1.8 mcg
14+ years	2.4 mcg	2.4 mcg

*** Pregnant woman 2.6 mcg, Lactating woman 2.8 mcg 

A microgram is 1/1,000,000 gram. It takes 1000 micrograms to equal 1 milligram. The daily requirement for vitamin B12 is very small. The USRDA has a safety factor to prevent the vitamin B12 deficiency. Pernicious anemia is an autoimmune disease that destroys stomach cells producing intrinsic factors. To be absorbed vitamin B12 must bind to intrinsic factors in your stomach. Vitamin B12 deficiency occurs when there is little or no intrinsic factor. A deficiency can cause megaloblastic anemia and neurological disorders. Without intrinsic factors, no amount of dietary or supplemental vitamin B12 will prevent or cure vitamin B12 deficiency.

Symptoms of vitamin B12 deficiency

Symptoms of vitamin B12 deficiency include - 

• dementia
• weakness 
• megaloblastic anemia
• constipation 
• depression 
• loss of appetite 
• numbness 
• mouth or tongue soreness
• weight loss
• confusion 
• fatigue 
• tingling in hands and feet

Vitamin B12 deficiency is usually treated by injections to bypass potential barriers to absorption. Some medical practices provide vitamin B12  injections based on vague symptoms without testing for vitamin B12  deficiency. Vague symptoms like brain fog, fatigue, bloating, gas, and forgetfulness. These vitamin B12  treatments are usually not covered by private insurance or Medicare. Treating a true deficiency may not require expensive vitamin B12 shots. One study of vitamin B12 deficiency indicates high doses of oral vitamin B12 2000 micrograms reduced to 1000 micrograms may be as effective as b12 shots. It comes down to each individual's ability to absorb vitamin B12. Before beginning an expensive series of vitamin B12 injections by medical practices marketed through email, mail, or television ads, see your doctor or get tested for vitamin B12 deficiency. High dose b12 is available without a prescription and costs far less than vitamin B12 shots. When buying vitamin B12 supplements look for the USP or other certification. To be effective vitamin B12 must be released in the stomach to bind with intrinsic factors. Taking high-dose vitamin B12 supplements is generally safe for most people. Absorption depends on the availability of intrinsic factors. For healthy people, about 10 micrograms to 500 micrograms are absorbed. Buying a 5000 microgram vitamin B12 supplement may not provide any more vitamin B12 than a 500 microgram supplement. 

Richest sources of vitamin B12

The best and high sources of vitamin B12 in your diet includes 

• seafood 
• eggs 
• fish 
• meat
• milk 
• poultry
• fortified foods and 
• milk products 

Plant foods have little or no vitamin B12. Almonds and other tree nuts have zero vitamin B12. Pumpkin and other seeds have zero vitamin B12. The same for kale and other leafy greens. Fortified breakfast cereals may or may not provide vitamin B12, you need to check the nutrition label. Unless you have pernicious anemia people eating little or no meat or dairy can still get enough dietary vitamin B12. Vegetarians and vegans can get vitamin B12 from fortified foods and oral vitamin B12 supplements. 

Here are 20 common high vitamin B12 foods 

• At number one is cooked beef liver, a 3-ounce serving provides 70 micrograms or almost 3000% of the RDA.
• 3 ounces of cooked clams provide 450% of the RDA at 10.7 micrograms.
• 3 ounces of canned sardines provides over 300% of the RDA at 7.6 micrograms.
• the same for three ounces of cooked wild-caught sockeye salmon.
• a 3 ounce serving of cooked trout provides 160% of the RDA at 3.8 micrograms.
• 3 ounces of cooked 80/20 ground beef has about 2.3 micrograms.
• 3 ounces of cooked lamb provides slightly more at 2.23 micrograms.
• 3 ounces of canned light tuna provides about 90%of the RDA at 2.2 micrograms.
• 3 ounces of cooked Cod provides 80% of the RDA at 1.9 micrograms.
• 3 ounces of cooked beef tenderloin has about 1.5 micrograms.
• 3 ounces of cooked squid provides 1.3 micrograms.
• One cup of low-fat milk provides 50% of the RDA at 1.2micrograms.
• 6 ounces of plain yogurt has about one microgram.
• One ounce of Swiss and other cheeses provides about 35% of the RDA at 0.85 micrograms.
• 3 ounces of cooked shrimp has about 0.8 micrograms.
• cooked chicken breast - a 3-ounce serving provides 0.23 micrograms, about 10 percent of the recommended dietary allowance.
• Chicken eggs - one large egg has 0.35 micrograms.
• 3 ounces of cooked turkey breast provides 30 percent of the RDA at 0.7 micrograms
• 3 ounces of lean cooked ham provides about half a microgram. 
• Fortified cereals with 0.6 micrograms per serving provide about 25% of the RDA.