Information On Food Sources With Iron & B12

Our body needs a wide range of vitamins and minerals to carry out different biological processes. Among those essential nutrients are iron and B12. Iron belongs to a class of minerals known as trace or micro minerals. Iron plays an important role in oxygen transport, brain development and immune function. Cobalmin, or B12, is a vitamin involved in amino acid conversions, DNA synthesis and nerve cell maintenance. To ensure an adequate intake of iron and B12, consume a balanced diet rich in whole grains, fruits, vegetables, lean proteins and healthy fats.

Iron Sources

Iron rich foods include meat, poultry, fish, leafy green vegetables and enriched grains. Examples of these foods include cooked clams, beef steak, spinach, Swiss chard, beef liver, soybeans, cooked oysters and ready-to-eat cereals.

B12 Sources

Unlike the rest of the B-complex vitamins, B12 is not found in foods of plant origin. Instead, it only occurs in foods originating from animal sources such as meat, poultry, fish, eggs, milk and cheese. One exception to this general rule is fortified foods such as ready-to-eat cereals or soy milk. Additional examples of rich sources of vitamin B12 include cooked clams, beef liver, herring, tuna, yogurt and cottage cheese.

Iron Bioavailability & Absorption

Iron is found in foods in two forms, known as heme and non-heme iron. Heme iron, which is found in animal sources such as meat, poultry and fish, is more readily absorbed by our bodies than non-heme iron. On the other hand, non-heme iron is found in plant food sources such as spinach, lentils and enriched grains.
Certain factors can enhance or impair iron absorption. To enhance the absorption of non-heme iron, consume it with a source of heme iron. For example, pair up your beans (source of non-heme iron) with cooked beef (source of heme iron); spinach with grilled fish; or lentils with braised chicken. In addition, vitamin C can significantly enhance the absorption of non-heme iron. So drink a glass of orange juice (source of vitamin C) with your breakfast cereal (source of non-heme iron) or add tomato sauce to your pasta.
Tannins, phytates, calcium and phosphorus are factors that hinder iron absorption. Tannins are compounds found in tea and coffee; phytates are found in fiber-containing foods. This is why it is advisable to drink tea or coffee between meals rather than with them.

B12 Absorption

The absorption of vitamin B12 requires the presence of intrinsic factor, a compound produced by the parietal cells of the stomach. Lack of this factor may impair vitamin B12 absorption and thereby increase the risk of deficiency.

Deficiency & Toxicity

Iron deficiency is the most common nutritional deficiency in the United States. Symptoms of iron deficiency anemia include weakness, fatigue, headaches and impaired mental performance. Symptoms of vitamin B12 deficiency include pernicious anemia, nerve damage, tingling or numbness sensations, memory loss and abnormal gait.
When it comes to iron and B12, more is not always better. Iron toxicity can cause gastrointestinal distress, joint pain, skin pigmentation and organ damage. Current evidence has not shown harmful side effects associated with high intakes of B12 from food or supplements. Always consult your doctor or registered dietitian and read the food label before taking an iron- or B12-containing supplement to prevent an accidental overdose.

Concerns for Special Populations

The vegetarian diet restricts the consumption of foods from animal origin. So it is important that individuals adopting the vegetarian diet ensure an adequate intake of iron and B12 to prevent the occurrence of potential deficiencies.

Moreover, women are especially susceptible to iron deficiency because of the blood loss associated with menstruation and pregnancy. This is one of the reasons that most obstetricians prescribe iron-containing multivitamins for pregnant and breastfeeding women