26 October 10 Vitamin B12 & SeafoodNeed another benefit from eating fish and seafood? It's vitamin B12. Most of us already know that fish/seafood (especially cold water marine fish) provide lots of heart-healthy omega-3 fats, and The American Heart Association recommends eating two servings of fish per week to help ensure that we get enough omega-3 fats, specifically DHA and EPA. This recommendation, however, is also a great way to get vitamin B12 without a lot of calories.
Why is vitamin B12 important?
Vitamin B12 (cobalamin) is needed in our diet for proper neurological function and blood formation. When our diet is deficient in vitamin B12, anemia can develop, along with nerve damage. Symptoms could include tingling and numbness in the extremities, problems walking, loss of concentration and memory, mood changes, visual disturbance, insomnia, and impaired bladder and bowel control.
Naturally-occurring vitamin B12 is bound to food proteins. The acidity in a healthy stomach allows the vitamin B12 to separate from food protein and travel into the small intestine where it can bind with Intrinsic Factor. This allows vitamin B12 to get absorbed into the blood stream. Although, when stomach acid secretion is compromised or if Intrinsic Factor cannot be produced in the stomach, vitamin B12 absorption will be compromised and a deficiency could develop over time. Fortified food sources and supplements contain the free form of vitamin B12 so stomach acidity is not necessary for digestion and absorption.
Folks who might need fortified foods or supplements:
- Over 50 years old - The Institute of Medicine (IOM) estimates that 10 – 30% of people over the age of 50 years may be unable to absorb naturally-occurring vitamin B12 due to much lower acid production in the stomach. Therefore, the IOM recommends that older people meet their vitamin B12 requirement mostly from fortified foods or supplements.
- Prolonged use of Proton Pump Inhibitors - These medications (e.g. Nexium, Prevacid, Prilosec, Protonix, etc) make the stomach less acidic. Over the long term, continued use of these medications can increase risk of vitamin B12 deficiency.
- Malabsorption Syndromes - Crohn's disease, gastric bypass surgery, removal of part of the small intestine, pancreatic insufficiency or malfunction, and other conditions that result in chronic diarrhea can all increase risk of vitamin B12 deficiency.
- Vegans & Their Infants - Plant foods do not have a reliable significant source of vitamin B12 so use of fortified foods and supplements is necessary for vegans in most parts of the world.
Where to get vitamin B12
Dietary sources of B12 include animal foods (e.g. fish/seafood, meat, poultry, eggs, milk, and cheese), fortified foods (e.g. fortified breakfast cereal, soy milk, etc), and supplements.
For healthy adults, the RDA is 2.4 mcg per day. This can be met with several servings of animal or fortified plant foods. For those of you wanting to eat heart-healthy, it is good to know that fish and seafood can provide both omega-3 fats and a magnificent source of vitamin B12. Take a look at the content of some selected fish/seafood sources (data from MyNetDiary.com).
Fish/Seafood (4 oz cooked) / Vitamin B12 (RDA%)
Clams / 5604%
Oysters / 1084%
Crab / 588%
Sardines / 510%
Coho salmon / 283%
Herring pickled / 242%
Lobster / 176%
Tuna light, canned / 170%
Tilapia / 105%
Shrimp / 84%
Curious as to how other animal and fortified plant foods stack up against fish and seafood? Here's a list of commonly eaten foods that contain significant sources of vitamin B12.
Other sources (4 oz cooked) / Vitamin B12 (RDA%)
Beef liver / 4713%
Chicken liver / 899%
Silk soy milk (1 cup) / 150%
Beef top round / 139%
Skim milk (1 cup) / 47%
Swiss cheese (1 oz slice) / 47%
Cottage cheese 2% fat (1/2 cup) / 40%
Egg (1 large) / 32%
Pork tenderloin / 31%
Turkey dark meat / 15%
Chicken breast meat / 14%
Apparently, there is very little risk of toxicity with high intake since absorption will simply decrease. Some of the excess intake is stored in the liver so it can take years for a vitamin B12 deficiency to develop in otherwise healthy people who simply go through periods of reduced
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This article can be found at http://www.mynetdiary.com/vitamin-b12-seafood-need-another-benefit-from.html