Phosphorus

Phosphorus plays a critical role in bone formation.

Phosphorus is widespread in many foods and is found in high amounts in foods that contain protein. Milk, meats, and eggs are good sources. Phosphorus is found in many processed foods as a food additive to enhance smoothness, binding, and moisture retention. In the form of phosphoric acid, it’s also a major component of soft drinks. Phosphoric acid is added to soft drinks to give them a sharper, or more tart, flavor and to slow the growth of molds and bacteria.

Nutrition and medical professionals have become increasingly concerned that the heavy consumption of soft drinks may be detrimental to bone health. Researchers have proposed 3 theories to explain why consuming soft drinks may be detrimental to bone health.

  1. Consuming soft drinks in place of calcium containing beverages leads to a deficient intake of calcium
  2. The acidic properties and high phosphorus content cause an increased loss of calcium because calcium is drawn from bone into the blood to neutralize the excess acid
  3. The caffeine found in many soft drinks causes increased calcium loss through the urine

People with kidney disease and those who take too many vitamin D supplements or too many phosphorus containing antacids can suffer from high blood phosphorus levels. Severely high levels of phosphorus can cause muscle spasms and convulsions. Phosphorus deficiencies are rare but can occur in people who abuse alcohol, in premature infants, and in elderly people with poor diets. People with vitamin D deficiency, hyperparathyroidism, and those who overuse antacids that bind with phosphorus may also have low blood phosphorus levels.

Source: Thompson, Janice, Melinda Manore, and Linda A. Vaughan. The Science of Nutrition. San Francisco, CA: Pearson Benjamin Cummings, 2011. Print.

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Vitamin B12

Vitamin B12 in our diet comes almost exclusively from meat, eggs, dairy products and some seafood. The stomach secretes intrinsic factor which is a protein necessary for vitamin B12 absorption in the small intestine. Since it is a water soluble vitamin, we would think that it would get excreted in our urine when consumed in excess. However, it has a unique feature of being stored in the liver which is important for anyone who’s consuming little vitamin B12 in the diet.

The RDA for vitamin B12 for adult men and women aged 19 years and older is 2.4 micrograms a day. Individuals consuming a vegan diet need to eat vegetable based foods that are fortified with vitamin B12 or take supplements to ensure that they maintain adequate blood levels of this nutrient.

A vitamin B12 deficiency is rare, but is associated with dietary insufficiency or reduced absorption. A deficiency of B12, like folate, is associated with cardiovascular disease due to high levels of homocysteine. Pernicious anemia is a condition when reduced absorption of vitamin B12 happens. It’s caused by inadequate secretion of intrinsic factor by parietal cells of the stomach.

Source: Thompson, Janice, Melinda Manore, and Linda A. Vaughan. The Science of Nutrition. San Francisco, CA: Pearson Benjamin Cummings, 2011. Print.

Folate

Folate is a water soluble vitamin and one of the B vitamins. Folic acid is the form of folate found in most supplements and used in enrichment and fortification of foods.

The RDA for folate for adult men and women aged 19 and older is 400 micrograms a day and 600 micrograms a day for pregnant women. Ready to eat cereals, bread, and other grain products are the primary sources of folate in the US. Other good food sources are liver, spinach, lentils, oatmeal, asparagus, and romaine lettuce. Losses of folate can occur when food is heated or when folate leaches out of cooked foods and the liquid is thrown out.

A folate deficiency can cause many different health effects including macrocytic anemia. Folate and vitamin B12 deficiencies cause elevated levels of homocysteine in the blood. When folate intake is not adequate during pregnancy, neural tube defects can occur.

Source: Thompson, Janice, Melinda Manore, and Linda A. Vaughan. The Science of Nutrition. San Francisco, CA: Pearson Benjamin Cummings, 2011. Print.

Copper

Copper is a trace mineral and is widely distributed in foods so a deficiency is rare.

The RDA for copper for men and women aged 19 years and older is 900 micrograms a day. Good food sources of copper include organ meats, seafood, nuts, and seeds. Whole-grain foods are also good sources.

Deficiency symptoms include anemia, reduced levels of white blood cells, and osteoporosis in infants and growing children.

Zinc

Without zinc, the body can’t grow, develop, or function properly. It’s estimated that more than one hundred different enzymes in the body require zinc in order to function.

Zinc absorption increases during times of growth, sexual development and pregnancy. High non-heme iron intakes can inhibit zinc absorption. Also, the phytates and fiber found in whole grains and beans inhibit absorption. However, dietary protein enhances zinc absorption, especially animal based proteins.

The RDA for zinc for adult men and women aged 19 years and older are 11 mg/day and 8 mg/day. Good food sources are red meats, some seafood, whole grains, and enriched grains and cereals. Zinc deficiency is a concern for people eating a vegetarian or vegan diet because zinc is more absorbable in animal based foods.

Source: Thompson, Janice, Melinda Manore, and Linda A. Vaughan. The Science of Nutrition. San Francisco, CA: Pearson Benjamin Cummings, 2011. Print.

Fluoride

Fluoride assists in the development and maintenance of teeth and bones.

Our needs for fluoride are small. There’s no RDA. The AI for children aged 4-8 is 1 mg/day, 9-13 years is 2 mg/day. For those 14-18 years old it is 3 mg/day. The AI for adults is 4 mg/day for men and 3 mg/day for women. It is available in many communities in the United States by fluoridated water and dental products. Fluoride is absorbed directly in the mouth into the teeth and gums and can also be absorbed from the GI tract once it’s ingested.

There are concerns for those who consume bottled water exclusively who might be consuming too little fluoride and increasing their risks for dental caries because bottled water doesn’t contain fluoride. Toothpastes and mouthwashes that contain fluoride are widely marketed and used by consumers in the US and these products can contribute as much fluoride in the diet as fluoridated water. Fluoride supplements are available only by prescription who are generally given to children who don’t have access to fluoridated water.

Source: Thompson, Janice, Melinda Manore, and Linda A. Vaughan. The Science of Nutrition. San Francisco, CA: Pearson Benjamin Cummings, 2011. Print.

Magnesium

Magnesium is one of the minerals that make up the structure of the bone. It’s also important for the regulation of bone and mineral status.

People who are adequately nourished generally consume enough magnesium in their diet. The RDA for magnesium changes by age groups and genders. For men 19-30 years of age the RDA is 400 mg and then increases to 420 mg for men 31 years and older. The RDA for women aged 19-30 is 310 mg/day and increases to 320 mg/day for women aged 31 and older.

Magnesium is found in green leafy vegetables like spinach. Also it is found in whole grains, seeds, and nuts. Other good sources include seafood, beans, and some dairy products. Refined and processed foods are low in magnesium. High protein intake enhances the absorption of magnesium.

Source: Thompson, Janice, Melinda Manore, and Linda A. Vaughan. The Science of Nutrition. San Francisco, CA: Pearson Benjamin Cummings, 2011. Print.



Osteoporosis

Osteoporosis is a disease characterized by low bone mass and deterioration of bone tissue. This leads to bone fragility and increases your risk for fractures. The bone tissue becomes more porous and thinner. These changes weaken the bone, leading to reduced ability of the bone to bear weight. Osteoporosis is the most important cause of fractures in the hip and spine in older adults. These fractures are extremely painful and can cause an increased risk of infection and other illnesses leading to premature death. About 20% of older adults who are suffering a hip fracture die within 1 year after the fracture occurs and death rates are higher for men than for women. Gradual compression fractures in the vertebrae of the upper back lead to shortening and hunching of the spine, also known as kyphosis.

Osteoporosis is a common disease and worldwide one in three women and one in five men over the age of 50 are affected. In the United States, more than 10 million people are diagnosed. Some factors that influence the risk for osteoporosis are age, gender, genetics, nutrition, and physical activity. Modifiable risk factors are smoking, low body weight, low calcium intake, low sun exposure, alcohol abuse, history of amenorrhea, estrogen deficiency, testosterone deficiency, repeated falls, and having a sedentary lifestyle.

 

Source: Thompson, Janice, Melinda Manore, and Linda A. Vaughan. The Science of Nutrition. San Francisco, CA: Pearson Benjamin Cummings, 2011. Print.

Potassium

Potassium and Sodium work together to maintain proper fluid balance and regulate the contraction of muscles and transmission of nerve impulses. Potassium also helps maintain blood pressure. Eating a diet high in potassium helps maintain a lower blood pressure.

The AI for potassium is 4.7 g/day for men and women aged 19 to 50. It is found in many fresh foods, mostly fruits and vegetables. Foods that are processed are usually loaded with sodium and decreases the amount of potassium. People with kidney disease aren’t able to regulate their blood potassium levels. Hyperkalemia or high blood potassium concentration, occurs when potassium is not efficiently excreted from the body. Severe hyperkalemia can alter the normal rhythm of the heart which can result in a heart attack or death. People with kidney disease must monitor their potassium intake.

Source: Thompson, Janice, Melinda Manore, and Linda A. Vaughan. The Science of Nutrition. San Francisco, CA: Pearson Benjamin Cummings, 2011. Print.

Vitamin A

Vitamin A is a fat soluble vitamin that plays a number of significant roles in the body. Vitamin A is critical to vision and the growth and differentiation of cells.

The RDA for vitamin A is 900 micrograms per day for men and 700 for women. Vitamin A is available in animal and plant sources. The most common animal sources are liver, eggs, and whole-fat dairy products. Vitamin A is also found in fortified reduced fat milks, margarine, and some breakfast cereals. Also dark green, orange, and deep yellow fruits and vegetables are good sources of beta-carotene and vitamin A. Carrots, spinach, mango, cantaloupe, and tomato juice are excellent sources because they contain beta-carotene.

People who are at risk for a deficiency include the elderly with poor diets, newborn or premature infants, young children with inadequate vegetable and fruit intakes, and alcoholics. Those with Chron’s disease, cystic fibrosis, celiac disease and diseases of the liver, pancreas, or gallbladder are also at risk for a deficiency.

Source: Thompson, Janice, Melinda Manore, and Linda A. Vaughan. The Science of Nutrition. San Francisco, CA: Pearson Benjamin Cummings, 2011. Print.