VITAMIN A :-Vitamin A is a group of unsaturated nutritional organic compounds, that includes retinol, retinal, retinoic acid, and several provitamin A carotenoids, among which beta-carotene is the most important. Vitamin A has multiple functions: it is important for growth and development, for the maintenance of the immune system and good vision.Vitamin A is needed by the retina of the eye in the form of retinal. Recommended daily allowanceVitamin ADietary Reference Intake
Sources
Vitamin A is found naturally in many foods
• cod liver oil Vitamin A deficiency causesVitamin A deficiency (VAD) is a lack of A in humans. It is common in poorer countries but rarely seen in more developed countries. (night blindness) is one of the first signs of VAD. , and complete blindness can also occur since Vitamin A has a major role in VITAMIN B12Vitamin B12, vitamin B12 or vitamin B-12, also called cobalamin, is a water-soluble vitamin with a key role in the normal functioning of the brain and nervous system, and for the formation of blood. It is one of the eight B vitamins. It is normally involved in the metabolism of every cell of the human body, especially affecting DNA synthesis and regulation, but also fatty acid metabolism and amino acid metabolism. Vitamin B12 deficiencyVitamin B12 is important for the way the body works, and people who don’t have enough of it may feel tired or have a lack of energy SOURCE :-in animal foods: meat, fish, poultry, eggs, and milk & dairy products. You can also get this important nutrient in some nutritional yeasts, as well as from fortified cereals and soy milk. VITAMIN B12 DEFICIENCY:-Not having enough vitamin B12 is called VITAMIN CVitamin C or L-ascorbic acid, or simply ascorbate (the anion of ascorbic acid), is an essential nutrient for humans and certain other animal species. Vitamin C refers to a number of vitamers that have vitamin C activity in animals, including ascorbic acid and its salts, and some oxidized forms of the molecule like dehydroascorbic acid. Ascorbate and ascorbic acid are both naturally present in the body when either of these is introduced into cells, since the forms interconvert according to pH. Food Sources
All fruits and vegetables contain some amount of vitamin C. VITAMIN C DEFICIENCY CAUSES :-
• Anemia Vitamin D :-RDA & TOLERABLE UPPER INTAKE OF VIT D
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REASONS FOR WIDESPREAD DEFICIENCY
- Latitude, season, time of the day
- Cloud cover and atmospheric pollution
- Time spent outdoors
- Customary dress and sunscreen use
- Skin pigmentation and age
- Vitamin D toxicity is rare. & caused by supplementing with high doses of vitamin D rather than sunlight.
- Tolerable upper intake level (UL), according to some research, is 4,000 IU/day for ages 9–71. Whereas another research concludes that in healthy adults, sustained intake of more than 1250 μg/day (50,000 IU) can produce overt toxicity after several months and can increase serum 25-hydroxyvitamin D levels to 150 ng/ml and greater
- PREDISPOSING FACTORS
- Primary Hyperparathyroidism: risk of hypercalcemia to any increased in vitamin D supplement.
- Maternal Hypercalcemia: increased fetal sensitivity to effect of Vit D leads to Mental retardation with facial deformities syndrome.
- Hypercalcemia:- polyuria, polydipsia can get deposits of calcium in soft tissues, kidney, liver ,heart& leads to pain & organ damage.
- Other Symptoms: anorexia, nausea, vomiting, weakness, insomnia nervousness , pruritis & finally leads to renal failure, proteinuria urinary casts, azotemia and metastatic calcification.
- Rickets, a childhood disease.
- It is characterized by impeded growth and soft, weak, deformed long bones that bend and bow under their weight as children start to walk.
- This condition is characterized by bow legs, which can be caused by calcium or phosphorus deficiency, as well as a lack of vitamin D; today, it is largely found in low-income countries in Africa, Asia, or the Middle East and in those with genetic disorders such as pseudovitamin D deficiency rickets.
- Rickets was first described in 1650 by Francis Glisson, who said it had first appeared about 30 years previously in the counties of Dorset and Somerset.[26] In 1857, John Snow suggested rickets, then widespread in Britain, was being caused by the adulteration of bakers’ bread with alum.
- The role of diet in the development of rickets] was determined by Edward Mellanby between 1918–1920.[30] Nutritional rickets exists in countries with intense year-round sunlight such as Nigeria and can occur without vitamin D deficiency.
- The dietary risk factors for rickets include abstaining from animal foods.
- Vitamin D deficiency remains the main cause of rickets among young infants in most countries, because breast milk is low in vitamin D and social customs and climatic conditions can prevent adequate sun exposure.
- In sunny countries such as Nigeria, South Africa, and Bangladesh, where the disease occurs among older toddlers and children, it has been attributed to low dietary calcium intakes, which are characteristic of cereal-based diets with limited access to dairy products.
- It is a disease in adults that results from vitamin D deficiency. Characteristics of this disease are softening of the bones, leading to bending of the spine, bowing of the legs, proximal muscle weakness, bone fragility, and increased risk for fractures.
- Osteomalacia reduces calcium absorption and increases calcium loss from bone, which increases the risk for bone fractures.
- It is usually present when 25-hydroxyvitamin D levels are less than about 10 ng/mL. The effects of osteomalacia are thought to contribute to chronic musculoskeletal pain, There is no persuasive evidence of lower vitamin D levels in chronic pain sufferers.
Excess
Excess
SYMPTOMS
TREATMENT
Stop Vit D & cut down the calcium intake. No relevance to sunlight exposure.
GRADES OF VIT D DEFICIENCY
| <5 ng/ml | Severe deficiency |
|---|---|
| <10 ng/ml | Moderate deficiency |
| <20 ng/ml | Mild deficiency |
| <30 ng/ml | insufficiency |
