Common foods, vitamin

Beriberi, Thiamine Deficiency. The recognition of vitamins and their importance to the health of human beings came about when Eijkman, a Dutch pathologist, was sent to Java in an attempt to cure an epidemic of beriberi that had appeared in one of the hospitals. Eijkman kept a flock of chickens on the hospital grounds to assist in discovering the disease agent he assumed was involved in the etiology of beriberi. These chickens were fed the scraps from the plates of the hospital patients—primarily poHshed rice, the common food in that part of the world (11). 

The body maintains an antioxidant network consisting of vitamins A, C, and E, antioxidant enzymes, and a group of related compounds called coenzyme Q, for which the general formula is shown below. The n represents the number of times that a particular group is repeated it can be 6, 8, or 10. Antioxidants are molecules that are easily oxidized, so they react readily with radicals before the radicals can react with other compounds in the body. Many common foods, such as green leafy vegetables, orange juice, and chocolate, contain antioxidants, as do coffee and tea. 

Many common foods (such as citrus fruits), pharmaceuticals (such as AspirinT ), and some vitamins (such as niacin, vitamin B3) are weak acids. When a weak acid dissolves in water, it does not completely dissociate. The concentration of the hydronium ions, and the concentration of the conjugate base of the acid that is formed in solution, depend on the initial concentration of the acid and the amount of acid that dissociates. 

In foods vitamin B2 occurs free or combined both as FAD and FMN and complexed with proteins. Riboflavin is widely distributed in foodstnffs, but there are very few rich sources. Only yeast and liver contain more than 2mg/100g. Other good sources are milk, the white of eggs, fish roe, kidney, and leafy vegetables. Since riboflavin is continuously excreted in the urine, deficiency is qnite common when dietary intake is insufficient. The symptoms of deficiency are cracked and red lips, inflammation of the lining of the month and tongue, mouth ulcers, cracks at the comer of the mouth, and sore throat. Overdose of oral intake present low toxicity, probably explained by the limited capacity of the intestinal absorption mechanism [417]. 

Fruits and vegetables are the most common food sources for vitamin C (15-18). In food, vitamin C exists as two vitamers L-ascorbic acid (AA) and its oxidation product, dehydro-L-ascor-bic acid (DHAA) (Fig. 1) (15,17-19). Total Vitamin C is the sum of the AA and the DHAA contents. A stereoisomer, isoascorbic acid (IAA) is often added to food as an antioxidant. Both LAA and its oxidation product, dehydroisoascorbic acid (DHIAA), can interfere in Total Vitamin C determinations. 

Thiamine (Vitamin B.). Citrus products are also good sources of thiamine. They proviae comparable amount or more of vitamin B, than foods that are known suppliers of this nutrient on the basis of nutrient density as measured by the Index of Nutrient Quality (INQ) (64). Listed in Table XI are the INQ of some common foods. The vegetables have high INQ since the index is calculated on unit nutrient per KCal, but citrus products are higher in INQ than some other fruits. Wholewheat bread, usually considered as a source of vitamin B. has an INQ much lower than that of orange juice. Thiamine in canned orange juice is rather stable. 

Common Food Sources and Selected Deficiency and Overdose Manifestations for Selected Vitamins of Potential Interest to Ophthalmic Practitioners... 

COMMON FOOD SOURCES Only microorganisms make B12 (not even plants make it). Large quantities are stored in the body, especially in the liver, enough to last 3 or more years, which is not the case for other water-soluble vitamins. We acquire vitamin B12 through ingesting meats (especially liver) and dairy products, including food fermented by bacteria, such as yogurt, soya sauce and sauerkraut. 

As far as Homo sapiens is concerned, milk is the only animal product that provides a significant amount of the vitamin (1-5 mg per 100 g) and, although there is some in liver, the best sources are fresh fruits (particularly citrus fruits, tomatoes, and green peppers), baked potatoes (17 mg per 100 g), and leafy vegetables. Some fruit, like guavas (300 mg per 100 g) and blackcurrants (200 mg per 100 g), are particularly rich in the vitamin but they contribute little to normal Western dietary intake. Table 5.1 gives a fairly comprehensive list of the vitamin C content of a wide variety of common foods. 

Vitamin Dietary Reference Intakes (DRI) Females (F) Males (M) (18-30 yrs old) Some Common Food Sources Consequences of Deficiency (Names of deficiency diseases are in bold)... 

The U. S. Department of Agriculture maintains the USDA National Nutrient Database for Standard Reference, which contains over 7000 food items with data on the energy content, minerals, vitamins, and other properties of nutritional interest. The table here includes about 600 common foods extracted from that database. The properties listed are the energy content (in effect, the enthalpy of combustion) the content of carbohydrates, proteins, and lipids (fats) the cholesterol content and the amount of sodium, potassium, calcium, magnesium, iron, copper, zinc, manganese, phosphorus, and selenium. AU values are given for a 100 gram sample of the food. 

Specific methods have been established for quite a large number of compounds or analytic problems. Among these are amino acids, sugars in food, common organic adds in food, vitamins, and additives (e.g., antioxidants) in polymers. Column manufacturers may have an applications database from which they can recommend a column and a method. However, it is recommended to rely on literature methods only, if the methods are well established and have been proved out in many laboratories. EPA methods or pharmacopoeia methods fall into this category, but a single reference on a method for an uncommon analyte should be viewed with caution. It is not unconunon that such a method does not work or does not work well when duplicated. In such a case, we are actually better off to develop a new method ourselves. 

The rate of absorption of dicoumarol can be increased by food. Two reports describe antagonism of the effects of warfarin by icecream, and another report attributes an increase in prothrombin time to the use of aspartame. However, the most common food-warfarin interaction is that due to foods containing vitamin K... 

None of these interactions is very well documented, and their clinical relevance is unclear. Note that vitamin K in food commonly interacts with warfarin, and these interactions are discussed in Coumarins and related drugs + Foods Vitamin Kj-rich , p.409. See also cranberry juice , (p.398), enteral and parenteral nutrition , (below), grapefruit juice , (p.411), mango , (p.408) and soya bean products , (p.408). 

Liposomes composed of phosphatidylcholine, cholesterol, and dl-(-tocopherol improved shelf life of vitamin C from a few days up to 2 months, especially in the presence of common food components which normally speed up decomposition, such as copper ions, ascorbate oxidase, and lysine (Kirby et al 1991). Calcium lactate was also encapsulated in lecithin liposomes, in this case to prevent undesirable calcium-protein interactions (Champagne and Fustier, 2007). The liposomal calcium levels of fortified soymilk were equivalent to those found in cow s milk. A synergistic effect of coencapsulation of vitamins A and D in liposomes promoted calcium absorption in the GI tract (Champagne and Fustier, 2007). 

Other common food lipids are the sterols and to-copherols. Sterols are generally present in natural oils as both the free sterol and sterol fatty esters. Animal fats exhibit solely cholesterol while plant lipids contain a range of phytosterols. Tocopherols are found in vegetable oils as a mixture of four iso-mers a-tocopherol (true vitamin E) and 3-, y-, and d-tocopherol. Four unsaturated analogs, tocotrienols, exist with the same numbering terminology and are particularly abundant in palm oil. 

Common foods and everyday substances such as oranges, lemons, vinegar, and vitamin C contain acids. 

Objectives toward which to aim in planning practical dietaries. The recommended allowances can be attained with a good variety of common foods which will also provide other minerals and vitamins for which requirements are less well known. 

Table 6.7 gives the vitamin A content of some common foods. These values can vary greatly with cultivar, stage of ripeness, etc. An accurate estimate of the vitamin A content of a food must include a detailed analysis of its carotenoids. 

Although deficiency is common, the vitamin is widespread in foods, and most diets will provide minimally adequate amounts to permit maintenance of central metabolic pathways. 

Table 5.8 B group vitamins content of common foods. 

Hard cheese, such as Cheddar, is one of the most concentrated of common foods 100 g (about 3.5 oz) supplies about 35% of the protein, 80%of the calcium, and 34% of the fat in the recommended daily allowance. Cheese is also a good source of some minerals and vitamins. 

Vitamin D is unique among vitamins in three respects ID it occurs naturally in only a few common foods ImaiNy in fish oils and a little in eggs and milkl. I2I it can be farmed in the btxfy and in certain foods by exposure to ifltraviolet rays, and I31 the active compound of vitamin D II, 25-lOHIi-Qjl functions as a hormone. 

Groupings by rank of common food sources of vitamin B-6 are given in the section on VITAMIN(S), Table V-5, Vitamin Table. 

Vitamin D is unique among the vitamins in two respects (1) it occurs naturally in only a few common foods (mainly in fish oils, and a little in liver, eggs, and milk), and (2) it can be formed in the body by exposure of the skin to ultraviolet rays of the sun—light of short wavelength and high frequency hence, it is known as the sunshine vitamin. 

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