Lynbrook | New Hyde Park | NY

vitamins

Iron: Deficiency, Food Sources, and Its Role in the Body

We have found that many of our clients or someone they know has experienced iron deficiency. Have you ever wondered what role iron plays in the body? Do you know what factors contribute to iron deficiency? Are you aware of what foods provide excellent sources of iron?

Iron is a mineral that is needed for all body functions, and every cell in the body contains and requires iron. The most significant role iron plays in the body is oxygen transport and storage. Roughly 75% of our iron is found in the blood in the form of hemoglobin and about 5% in the form of myoglobin. Hemoglobin is a protein-iron compound responsible for carrying the oxygen from our lungs to the rest of our body. Myoglobin is a form of hemoglobin that is found in the muscles and is responsible for carrying and storing oxygen for the muscles, specifically the skeletal and cardiac muscles. The less iron we have, the less hemoglobin is produced, and therefore less oxygen is delivered to our tissues. Iron also has a role in energy production and is present in a variety of enzymes that aid in chemical. In addition, iron aids the immune system in maintaining its function.

The largest factor that contributes to iron deficiency is the inability to adequately obtain appropriate levels from the diet. Iron is the most common single nutrition deficiency in our population, with the most significant deficiencies found in menstruating women. Men have a reserve of about 1000mg and a loss of about 1mg a day. Menstruating women on the other hand have a reserve of 200-400mg with a loss of 1.5-2.4mg per day. Other factors that contribute to iron deficiencies include low stomach acid, removal of a part of the stomach, malabsorption syndromes, calcium phosphate salts, tannic acids, antacids, and phytates.

Hypochromic microcytic anemia, also known as iron deficiency anemia, is the most common deficiency. The red blood cells are smaller than normal, and they are paler in color due to decreased levels of hemoglobin. The decreased hemoglobin results in oxygen starved tissues which then present symptoms including listlessness, difficulty swallowing, paleness, heart palpitations with exertion, and a general lack of well being. Even with the absence of anemia, decreased levels of iron are detrimental to your health. Symptoms include decreased learning ability, decreased endurance, fatigue, decreased tolerance to cold, depression, hair loss, brittle nails, headaches, and a craving for salt.

Iron in food comes from two different forms: heme iron and non-heme iron. Heme iron comes from animal flesh, while non-heme iron is found in plant food and dairy products. The absorbability of iron in different food varies according to the source. Organic iron found in red meat is the most absorbable at about 10-30%. Inorganic iron found in plant products is only absorbable at about 2-10%. The best 6 sources of iron are high in other nutrients that help aid iron absorption. For example, iron rich green vegetables are also high in vitamin C, copper, and manganese which all aid iron absorption. Shrimp, venison, and beef are also high in absorption boosting amino acids. Cooking in cast iron cookware has also been shown to enhance absorption. Some of the best food sources other than meat include spinach, Swiss chard, tofu, soybeans, pumpkin seeds, shrimp, lentils, olives, and herbs.

There are numerous guidelines that quantify the amount of nutrients that we need on a daily basis. The RDA is 18mg for women under the age of 51 and 8mg for men and women over the age of 51. The ODI for iron is 15-25mg for men and 18-30mg for women. While supplementation can be helpful, it is important to consume our minerals and vitamins through a whole food diet. Track your food for a week and calculate the mineral and vitamin intake to identify deficiencies in your diet.

 

By Pamela Geisel

References
Lieberman, S & Bruning, N. (2007). The Real Vitamin & Mineral Book. (4th edition). New York: Avery.
Mateljan, G. (2007). The World’s Healthiest Foods: Essential Guide for the Healthiest Way of Eating. (1st edition). Washington: GMF Publishing.
McGuire, M & Beerman, K. (2013). Nutritional Sciences from Fundamentals to Food. (3rd edition). California: Woodsworth.

Vitamin D: Why Is It Important and Where Can You Find It?

Vitamin D is an unconventional vitamin for two reasons. The first reason is that our bodies are able to make vitamin D with exposure to the sun. The second reason is vitamin D, when in its active form calcitriol, has a hormone-like effect on mineral absorption, bone mineralization, and various secretions.

Vitamin D is important for bone and muscle health, immunological activity, cancer risk, calcium levels, and cell activity. Vitamin D is probably best known for its role in maintaining bone density. When combined with calcium, vitamin D prevents bone loss and promotes an increase in bone density. This helps reduce the rate of hip fractures, which has not been seen with calcium supplementation or hormone therapy alone. The improved bone mineralization is directly correlated to an increase in longevity and quality of life. Vitamin D is also important in dental health and maintaining strong, healthy teeth.

Vitamin D is also important to maintain calcium levels. The active form of vitamin D works with parathyroid hormone (PTH) to maintain calcium levels in the blood. It does this by increasing intestinal absorption, increasing reabsorption of calcium by the kidneys, and stimulating the release of calcium from the bones when levels are low. It also works in the reverse manner if levels are too elevated.

Vitamin D has been recognized to have antitumor properties. In previous studies, vitamin D supplementation resulted in pancreatic cancer risk to be reduced by half in both men and women. In addition, colorectal cancer risk was reduced by half in women with increased levels of vitamin D in combination with calcium. Vitamin D has an immunological benefit by preventing excessive inflammatory activity. Our immune cells have receptors for vitamin D, specifically our T cells. This is significant because many autoimmune diseases have a T cell component. Vitamin D therefore plays a role in the prevention and treatment of diseases like Type 1 diabetes, multiple sclerosis, and rheumatoid arthritis.

The color key represents the likelihood of Vitamin D synthesis in February. Dark blue indicating it is more unlikely and Red indicating it is likely.

The largest factor related to a vitamin D deficiency is limited sun exposure. This could be for a variety of reasons including being homebound, living at northern latitudes, use of sunscreen, full body coverage of clothing, and occupations without sunlight. Darker skin tones also contribute to vitamin D deficiency because of the increased melanin. Symptoms of insufficient vitamin D levels include altered muscle function, malabsorption of calcium, rickets, hypocalcemia, osteomalacia, osteoporosis, bone irregularities, and autoimmune diseases.

Foods are generally low in Vitamin D with the richest foods being fish liver oils and fatty saltwater fish. These include sea bass, halibut, swordfish, herring, tuna, and cod. Other sources include sardines, shrimp, and eggs. Milk and dairy products can be a good source because they are often fortified with Vitamin D.

There are several recommendations that quantify the amount of nutrients that we need on a daily basis but we are interested in the Recommended Dietary Allowance (RDA) and the Optimum Daily Intakes (ODI). The RDA is 600IU for vitamin D and the ODI is 1000IU. Careful attention needs to be applied to our diets to ensure that we are consuming as much of our vitamin D through a whole food diet as possible. Supplementation can aid in meeting requirements, but we cannot rely solely on them because of the significant number of nutrients not yet identified.

 

References
Lieberman, S & Bruning, N. (2007). The Real Vitamin & Mineral Book. (4th edition). New York: Avery. Mateljan, G. (2007). The World’s Healthiest Foods: Essential Guide for the Healthiest Way of Eating. (1st edition). Washington: GMF Publishing.
McGuire, M & Beerman, K. (2013). Nutritional Sciences from Fundamentals to Food. (3rd edition). California: Woodsworth.