High Risk Groups for Poor Vitamin Status

Smoking a cigarette eases feeling of hunger by dulling the hunger singers. Smokers are then able to curtail energy and nutrient intake. Smokers have been found to have a poorer nutritional status of a number of micronutrients than nonsmokers. Smokers tend to have lower intakes of vitamin A, ß-carotene, folate, and vitamin C. Research has shown that compared with nonsmokers, smokers require an additional 35 milligrams per day of vitamin C to maintain adequate body stores. Smokers where found to have significantly lower levels of vitamin E in lung alveolar fluid in comparison to nonsmokers. These reduced nutrients levels may contribute to the health risks associated with smoking.

Skipping meals and dieting to lose weight frequently compromise micronutrient intake. Diets that omit or severely restrict whole categories of foods, can have serious negative impact on micronutrient status. For example, diets that eliminate all animal foods provide no vitamin B12, and may also be inadequate in thiamin and vitamin D. In general it is difficult to meet all micronutrients requirement on very low calorie diets (VLCD).

Commonly used medications are known to interfere with the absorption and/or metabolism of nutrients and alter nutrient needs. These include antibiotics, anti-convulsants, anti-ulcer drugs, anti-metabolites, diuretics, laxatives, corticosteroids and oral contraceptives, as well as any other drugs that decrease appetite, cause vomiting or diarrhoea or alter the intestinal flora. Some medications represent a particular problem especially since they are taken chronically.

Decrease Food Intake. Medications can reduce food intake by decreasing appetite, altering the sense of taste and smell, drying the mouth, or leading to mouth lesions that make eating difficult.

Example: Appetite suppressants directly affect food intake by decreasing appetite.

Example: Several cancer medications and treatments may cause nausea, vomiting, sore or dry mouth resulting in poor food intake.

Decrease Absorption/Increase loss. Some medications can interfere with nutrient absorption or increase losses.

Example: Laxatives move food rapidly through the intestine which reduce the time available for nutrient absorption. Also laxatives may also trap nutrients causing them to be excreted.

Example: Some cholesterol lowering medications reduce cholesterol by removing bile acids. Bile acids are needed to absorb the fat-soluble vitamins A, D, E, and K. As a result some cholesterol lowering medications can reduce absorption of fat-soluble vitamins.

Alcohol, particularly in excess, interferes with the availability and activation of almost every vitamin. The excessive use of alcohol can alter the metabolism of vitamin D and is associated with low serum levels of folate, thiamin, vitamin B12 and vitamin B6. Alcoholics and excessive drinkers often have extremely low liver stores of vitamin A, even when blood levels are normal. Low serum ß-carotene concentrations were found in regular alcohol drinkers, with still lower levels seen in drinkers who smoke. Ingestion of excessive alcohol has been shown to interfere with intestinal absorption of vitamin C.

Thiamin: Alcohol impairs the absorption of thiamin. Additionally, the liver damage caused by excess alcohol impairs the activation of thiamin for optimal use by the body. Severe thiamin deficiency causes major brain dysfunction characterised by disordered thinking and memory as well as disturbances of motor coordination.

Folate: In the presence of alcohol, the body behaves as if it were actively trying to expel folate from its sites of action and storage. The liver releases folate from its stores into the blood. As the blood folate rises, the kidney reacts as if there was an excess of folate and begins to excrete the perceived "excess". Alcohol further aggravates the situation by interfering with the action of the leftover folate. Production of new cells is inhibited especially those of the intestine and the blood. Damage to the intestine from both folate deficiency and alcohol toxicity impairs the ability of the gut from normally releasing and retrieving folate, and it also fails to absorb any folate from food.

Vitamin B6: Acetaldehyde, one of the products of alcohol metabolism, removes vitamin B6 from it protective binding protein causing it to be destroyed.

Vitamin B12: Alcohol inhibits vitamin B12 absorption directly, and indirectly, by suppressing the secretion of intrinsic factor which facilitates the vitamin's absorption from the intestine into the bloodstream.

Adolescents experience a period of rapid growth which increases their needs for vitamins. These high nutrient demands may not be met by their typical diet.


Increased nutrient demands
	Increased energy demands increase the needs for thiamin, riboflavin, and niacin to release energy from carbohydrates.
	There is an increased demand for vitamin B6, folate, and vitamin B12 because of tissue synthesis.
	There is also an increased requirement for vitamin D (rapid skeleton growth)
	Vitamin A, C and E are needed for new cell growth.

Teenagers who avoid fruit and vegetables and smoke cigarettes may be at risk for vitamin C deficiency.

Generally, sufficient vitamin intake can be achieved by a well-chosen diet without the need for supplements. The exceptions are those that have an eating disorder or chronic disease, or who chronically make bad food choices.

Increased nutritional requirements during pregnancy and lactation are universally acknowledged. Folate and iron are especially needed in greater amounts during pregnancy as they are required for the increases in maternal red blood cell production and the rapid fetal and placental growth. Therefore the recommendation for folate and iron increase significantly during pregnancy. Folate is also lost through milk during lactation.

	poor diet
	dental disorders
	lack of mobility
	reduced energy needs (reducing micronutrient intake)
	drug/nutrient interactions
	chronic illness
	economic restraints
	difficulty digesting and/or absorbing nutrients

Vitamin D: The requirement for vitamin D is dependent on the intake of calcium and phosphorous, the person's age, sex, degree of exposure to sunlight and the amount of skin pigmentation. Elderly people are at risk for vitamin D deficiency because of inadequate diets and decreased sunlight exposure (especially institutionalized and homebound elderly).

For a number of reasons the elderly represent a large and expanding segment of the population at risk for nutritional deficiencies.

Low-birth-weight (LBW) infants (less than 2500 g) are at risk for serious health problems and increased mortality. Most fetal nutrient stores are deposited during the last 3 months of pregnancy therefore the premature infant begins life with compromised nutritional stores. Premature infants have been found to have low plasma vitamin C levels and a low vitamin A status, and a proneness to vitamin E deficiency. Vitamin supplementation would be necessary for premature babies as they can drink limited amounts of milk and their nutrient stores are minimal. The nutrients of particular concern are the fat-soluble vitamins, folate, vitamin C and vitamin B6.

Diabetes. Diabetic individuals may be at risk of marginal thiamin deficiency and low status of other B vitamins, vitamin C, and vitamin D.

Cancer. Cancer patients are at increased risk for vitamin deficiencies for various reasons. Factors promoting deficiencies in cancer include inadequate digestion, malabsorption, vomiting and the effects of cancer treatment (radiation therapy, chemotherapy, surgery).

Examples
	Diarrhoea. Food moves rapidly through the intestine which reduces the time available for nutrient absorption, therefore persistent diarrhoea may cause multiple nutrient deficiencies.
	Inflammatory bowel diseases (Crohn's disease and ulcerative colitis). These inflammatory diseases have many complications that lead to deficiencies particularly of vitamin B12, folate, vitamin C and fat-soluble vitamins.
	Bacterial overgrowth. The bacteria can compete with the body for vitamin B12 and folate leading to deficiencies.
	Short Bowel Syndrome. Malabsorption of vitamin B12 and fat-soluble vitamins can occur when the ileum is resected.

Liver Cirrhosis. Deficiencies commonly occur in liver disease because the liver has a central role in the metabolism and storage of vitamins. Co-existing factors like malabsorption, alcoholism, and malnutrition aggravate the deficiency.

	Deficiencies of thiamin, vitamin B6, riboflavin and folate are common.
	Fat-soluble vitamins may also be malabsorbed if steathorrheoa (fatty diarrhoea) develops.

Fat Malabsorption. Disorders involving the stomach, pancreas, intestine, and the liver all lead to fat malabsorption. Fat-soluble vitamins are excreted in the stools along with the unabsorbed fat.