Hypervitaminosis and Hypovitaminosis



Hypervitaminosis and Hypovitaminosis

Introduction

This paper shed some light on the conditions of Hypervitaminosis - Excessive intake of vitamins, and Hypovitaminosis - Deficiency of vitamins.

Discussion

Hypervitaminosis

Hypervitaminosis is a rare condition, caused by an excessive intake of vitamins. This problem does not involve any major consequence for health. Hypervitaminosis corresponds to an excessive intake of vitamins A and D. These, when exceeding the needs of the organism, and which are not eliminated via urine, can cause a stock, and develop a disastrous toxicity for metabolism (Woelfel 1970).

Other vitamins (B & C) are rapidly eliminated via urine, while vitamins A, D, E or K are installed in fatty tissues. These are called soluble vitamins. An overdose of vitamin D causes gastrointestinal derangement, nausea, and bone calcification, severe thirst, dehydration.

These are the most common symptoms: vomiting, nausea, headaches, dizziness, liver and kidney function, bleeding, skin problems.

Classification

Acute Hypervitaminosis A

Relatively rapid absorption with low plasma clearance occurs a few hours after being ingested or injected high doses of vitamin A.

Chronic Hypervitaminosis A

Appears when smaller doses of vitamin A are administered over a longer period of time (months, years) (Birkhaug 1938).

Source

It should also be noted that food cause hypervitaminosis is naturally very difficult. While when it happens by ingesting synthetic supplements or pharmaceuticals hypervitaminosis may be the most serious case (Woelfel 1970).

Doses

The toxic doses differ greatly between the precursor cholecalciferol and the activated hormone calcitriol. Dating back to the plant kingdom ergocalciferol seems somewhat weaker than cholecalciferol (Birkhaug 1938).

Cholecalciferol

An acute single dose for an adult requires about about 50 mg (or 2 million IU ). Thus, in adults a chronic overdose occurs, usually 1-2 mg daily (which are about 200 times the RDA , 40,000 IU) for many months. There have been cases of oral overdose due to manufacturing errors, and industrial accidents.

Over the maximum dose that can be ingested daily without serious side effects, yet are unclear. Blood levels of 25 (OH) vitamin D 3 increases over a wide dose range of up to a daily dose, which corresponds to the maximum synthesis performance of the skin, not in toxic areas (Birkhaug 1938).

Calcitriol

Calcitriol is among others in chronic renal failure given for treatment and prevention thereby induced bone metabolism disorders. The dose may be given daily from 0.12 micrograms to about 1 ug under close medical supervision. The toxic threshold limit for adults is at 250 micrograms. The half-life of a given external calcitriol in blood is short, with only three to six hours.

Calcitriol improves the absorption of calcium and phosphate ions in the small intestine. The increased calcium and phosphate level in serum improves bone mineralization. In high concentrations, calcitriol may also stimulate osteoclast differentiation. Thus the calcium and phosphate ion concentration is increased in the blood (Woelfel 1970).

Health Consequences

Hypervitaminosis A: patients experience symptoms similar to those of a tumor brain, headache, vomiting, bone pain, blurred vision.

Hypervitaminosis D: Its symptoms are similar to those of an excessive presence of calcium, such as weakness, fatigue, headache and nausea (Woelfel ...