Presentation
Night blindness or nyctalopia, in which the eyes have difficulty in adjusting to dark is one of the earliest and common symptoms of VAD. Some young children may present with small, irregular patches of keratinization, called Bitot spots, in the conjunctiva. Deficiency of vitamin A leads to a reduction in the amount of visual pigments in the eye. Lack of pigments like rhodopsin and iodopsin affects transduction of light leading to poor vision and blindness. Drying of conjunctiva and cornea causes xerophthalmia which may be followed by progressive softening and thinning of the cornea called keratomalacia. If left untreated, it may result in infection and rupture of cornea. This degenerative change is yet another reason for blindness.
People deficient in vitamin A may also have dry hair and skin, and brittle nails. Malnutrition leads to follicular hyperkeratosis or phrynoderma, manifested by the presence of skin lesions and hyperkeratotic papules. These are often found in shoulders, buttocks and extremities. VAD increases the chance of infections by impairing the humoral and cell-mediated immunity. In some cases, keratinization of mucous membranes and deposition of periosteal bone may also be noted.
Entire Body System
- Anemia
INTRODUCTION: Micronutrient deficiency is an unquestionable public health problem, specially anemia and vitamin A deficiency (VAD). [ncbi.nlm.nih.gov]
Causes of vitamin deficiency anemias, also known as megaloblastic anemias, include: Folate deficiency anemia. Folate, also known as vitamin B-9, is a nutrient found mainly in fruits and leafy green vegetables. [mayoclinic.org]
Vitamin A deficiency is associated with anemia, and there may be several mechanisms by which vitamin A deficiency could cause anemia, including impairment of iron metabolism, and immune dysfunction and associated anemia of infection [ 23 ]. [nutritionj.biomedcentral.com]
- Asymptomatic
Eight patients were studied, three boys had clinical vitamin A deficiency, three had asymptomatic deficiency, and two young men with Dent's disease and impaired renal function had normal retinol values. [ncbi.nlm.nih.gov]
With the high prevalence of vitamin A deficiency, however, this testing is not usually done if patients are asymptomatic. [kidsnewtocanada.ca]
She was asymptomatic in daylight, but almost blind in the dark to the extent where she found driving difficult unless weather conditions were clear and bright. [journalofoptometry.org]
- Anorexia
Carotenosis may also occur in severe hypothyroidism and anorexia nervosa, possibly because carotene is converted to vitamin A more slowly. Complete recovery usually occurs if vitamin A ingestion stops. [merckmanuals.com]
Measles often precipitates xerophthalmia because it leads to lowered food intake (in which anorexia and stomatitis may be factors) and to increased metabolic demands for vitamin A. [provisu.ch]
At this time, she complained of increased vomiting, steatorrhea and diarrhea (8-10 times/day), without abdominal pain or anorexia, which partially responded to antibiotic prescription. [scielo.isciii.es]
Respiratoric
- Sore Throat
CAUTION: Excess consumption may cause burning sensations in throat, stomach, or rectum [go4worldbusiness.com]
Gastrointestinal
- Loss of Appetite
Its deficiency leads to poor growth, loss of muscular control, loss of appetite, weakness and hairfall. Folic acid (Vitamin B10) is essential for formation of RBC, and it also increases the appetite. [compete.etutor.co]
Overconsumption of vitamin A can lead to jaundice, nausea, loss of appetite, irritability, vomiting, and even hair loss. [healthaliciousness.com]
- Failure to Thrive
Vitamin A deficiency should be considered in the differential diagnosis of nonhealing corneal ulcers in children, especially those with systemic syndromes and failure to thrive. [ncbi.nlm.nih.gov]
In children, toxicity can cause pruritus, anorexia, and failure to thrive. Hepatomegaly and splenomegaly may occur. In carotenosis, the skin (but not the sclera) becomes deep yellow, especially on the palms and soles. [merckmanuals.com]
Cardiovascular
- Heart Disease
We observed a 46, XY infant with atrophy of the optic nerve, complex congenital heart disease including a double outlet right ventricle, hypoplasia of the right pulmonary artery and lung, eventration of the diaphragm, and ambiguous genitalia. [ncbi.nlm.nih.gov]
It can also lead to an increased risk of chronic diseases, such as heart disease or diabetes, in adulthood. Although stunting is declining, the rate of decline is too slow. [cehjournal.org]
Potassium is an important component of cellular and bodily fluids that help regulate heart rate and blood pressure. Thus, they provide protection against stroke and coronary heart disease. [sanam.pro]
The ACE study (Adverse childhood experiences) from the Center for Disease Control and Prevention demonstrates that traumatic experiences in early development lead to increased risk for alcohol and drug addictions, depression, fetal death, heart disease [coloradoplaytherapy.com]
Skin
- Dry Skin
Other symptoms include dry skin, hardening of epithelial cells elsewhere in the body (such as mucous membranes), and impaired growth and development. [britannica.com]
Eczema and other skin problems are caused due to vitamin A deficiency that leads to dry, itchy skin. Dry Eyes Eye problems are related to vitamin A deficiency. The inability to produce tears is the first sign of vitamin A deficiency. [byjus.com]
Other symptoms include: Dry eyes Eye inflammation Dry skin Dry hair Broken fingernails Decreased resistance to infections Diagnosis of Vitamin A Deficiency The diagnosis is based on clinical symptoms and a low level of vitamin A in the blood. [adoptionnutrition.org]
Dry, scaly, thickened skin with prominent follicular scale Dry lips and thickened tongue Keratinisation of the urinary, gastrointestinal and respiratory tracts Other symptoms and signs Impaired immunity leading to gastrointestinal and respiratory tract [dermnetnz.org]
- Follicular Hyperkeratosis
Phrynoderma is a rare form of follicular hyperkeratosis associated with deficiencies in vitamins A or C or essential fatty acids. [ncbi.nlm.nih.gov]
Poor adaptation to darkness (nyctalopia) Dry skin Dry hair Pruritus Broken fingernails Keratomalacia Xerophthalmia Corneal perforation Follicular hyperkeratosis (phrynoderma) secondary to blockage of hair follicles with plugs of keratin. [emedicine.medscape.com]
Malnutrition leads to follicular hyperkeratosis or phrynoderma, manifested by the presence of skin lesions and hyperkeratotic papules. These are often found in shoulders, buttocks and extremities. [symptoma.com]
Vitamin A deficiency is one of several hypovitaminoses implicated in follicular hyperkeratosis. Night blindness is the difficulty for the eyes to adjust to dim light. [en.wikipedia.org]
Eyes
- Night Blindness
Her vitamin deficiencies were corrected with appropriate supplements and her night blindness resolved. [ncbi.nlm.nih.gov]
San Diego: Academic Press, Inc., 1998. vitamin A deficiency A condition characterised by night blindness, keratomalacia, increased urogenital and nasopharyngeal infections, and dry eyes. vitamin A deficiency A condition characterized by night blindness [medical-dictionary.thefreedictionary.com]
Night Blindness Acute vitamin A deficiency results in night blindness. Vitamin A supplements have helped women to adapt to darkness by 50% within six weeks. Infertility Vitamin A deficiency results in infertility in both men and women. [byjus.com]
- Bitot's Spots
Key terms Bitot's spots — Bitot's spots are superficial, foamy gray, triangular spots on the white of the eyeball. Carotenoids — Carotenoids are yellow to deep-red pigments. [medical-dictionary.thefreedictionary.com]
[…] were observed in 6.7% of the children with Bitot's spots, bilateral temporal spots in 58.1%, unilateral temporal spots in 25.6%, and 9.4% were not classified. [archive.unu.edu]
Bitot’s spots at the temporal limbus. Clare Gilbert Figure 2. Bitot’s spots at the temporal limbus. Clare Gilbert Bitot’s spots Bitot’s spots (Figure 2) are characteristic of VAD and are not caused by any other condition. [cehjournal.org]
Rare – Bitot's spots Bitot's spots (Figure 2 ) are characteristic of VAD and are not caused by any other condition. [ncbi.nlm.nih.gov]
Bitot's spot is highly suggestive of vitamin A deficiency and, sometimes, chronic conjunctival inflammation. [nejm.org]
- Lacrimation
The signs indicating VAD include [1]: Dryness: The lacrimal gland fails to produce tears which causes an insufficent tear film covering the cornea. A poor tear film means pain, poor vision and puts the eye at risk for corneal ulcers and infections. [optometrystudents.com]
Neurologic
- Seizure
If neonatal calves cannot acquire adequate vitamin A, seizures or other neurologic signs are possible from increased cerebrospinal fluid pressure. Continued low vitamin A can lead to severe diarrhea that is often fatal. [bovinevetonline.com]
Certain prescription drugs, such as some anti-seizure medications, can interfere with absorption of this nutrient. [mayoclinic.org]
Some of the signs and symptoms associated with vitamin A toxicity are: Headache Nausea and vomiting Double or blurred vision Fatigue Weakness Dizziness Seizures Irritability Muscle pain Bone and joint pain Weight loss Hair loss Mucous membrane dryness [labtestsonline.org]
Severe cases of encephalitis can lead to seizures, hearing loss, brain damage or death.</p><p>Children with vitamin A deficiency who get measles can become blind. [aboutkidshealth.ca]
Blood pressure higher than 160/110, along with other symptoms such as proteinuria, blurry vision, epigastric pain, headache and edema without and with seizures, was considered severe pre-eclampsia and eclampsia, respectively. [journals.plos.org]
- Clumsiness
Parents may notice that their young child is clumsy in the dark or fails to recognize people in a poorly lit room. Night blindness occurs because vitamin A deficiency reduces the rhodopsin in the rods of the retina. [provisu.ch]
Workup
Serum concentration of retinol is an important measure of vitamin A in the body and can be examined using high-performance liquid chromatography. In children below the age of 12 years, serum concentration below 0.7 mg/L is considered to be low and of concern.
RBP can be measured using immunologic assay and is less costly when compared to serum retinol levels. Levels of zinc can affect the serum retinol concentration and hence is included in some laboratory investigations for checking deficiency. Albumin levels are also suggested as it gives an indirect measure of the vitamin in serum.
If anemia is suspected, a complete blood picture is recommended. This will also indicate any kind of infection or sepsis. To understand the nutritional status, liver function test and evaluation of electrolytes are useful. Dark adaptation test is also recommended in some cases [8].
Colonoscopy
- Colitis
Summary Background This study was designed to determine the effects of two dosages of vitamin D supplementation on inflammatory biomarkers in patients with ulcerative colitis (UC). [clinicalnutritionespen.com]
[…] doi.org/10.1186/s12937-019-0441-7© The Author(s). 2019Received: 18 December 2018Accepted: 4 March 2019Published: 11 March 2019 Abstract Background The optimum dosage for vitamin D supplementation has not yet been elucidated in patients with Ulcerative colitis [muckrack.com]
Treatment
Subclinical forms of vitamin A deficiency may not have many symptoms and can be resolved by taking more of vitamin-rich foods. Eggs, green leafy vegetables, fortified foods, carrots, liver and beef are all good sources of vitamin A. Those who present with clinical VAD are recommended to take oral vitamin A supplements. The recommended dose for adults is 10,000 IU while in children the dosage varies with the age as given below:
- Below 3 years: 2,000 IU
- 4-8 years: 3,000 IU
- 9-13 years: 5,665 IU
- 14-18 years: 9,335 IU
For severe forms of VAD, dose range of 200,000 IU is often suggested. Using oral supplements in children below 5 years reduced the mortality rate by almost 24% [9].
Prognosis
Deficiency of vitamin A can affect many physiological functions in the body and lead to complications. Children of preschool age and pregnant women are at higher risk of developing these conditions. Xerophthalmia, night blindness and anemia are associated with VAD.
When present, vitamin A deficiency may worsen an infection and severe form of VAD may lead to death. In many cases, the condition can be resolved by intake of vitamin A supplements or a well-balanced diet. Providing vitamin A supplements for children below the age of 6 months was found to reduce mortality rate by 21% [7]. Loss of vision due to the deficiency is often permanent. Night blindness improves when the serum concentration of retinol increases. If the deficiency is caused by any of the secondary factors like an underlying disease, the condition can be improved only by treating the disorder. Recurrence is also common in cases where a well-balanced diet is not followed.
Etiology
Malnutrition is one of the primary causes of vitamin A deficiency. Dietary insufficiency of this vitamin is very common among people who have rice as their staple food. Conditions of protein-energy malnutrition like Marasmus and Kwashiorkor also lead to vitamin A deficiency. When the intake of this vitamin through diet is insufficient, it affects vision and impairs tissue function in general.
Secondary causes like increased requirement of vitamins, defect in intestinal absorption and metabolic changes also result in VAD. The requirement of vitamin A is found to be more in children who are sick leading to a deficiency of this vitamin. VAD is associated with xerophthalmia and measles [2]. Defect in intestinal absorption of fats due to gastrointestinal diseases like inflammatory bowel disease, cystic fibrosis, obstruction in the bile duct or pancreatic insufficiency, will in turn affect the absorption of fat-soluble vitamins. The risk of VAD is increased in people who had duodenal bypass surgery. Other dietary factors like deficiency of zinc and abetalipoproteinemia can affect the absorption of carotenoids and thus lead to VAD.
Epidemiology
Vitamin A deficiency is prevalent in most of the developing countries including South East Asia and Africa [2]. Economically deprived population like refugees, immigrants and displaced communities face severe form of vitamin A deficiency [3]. Most of the developing countries have clinical form of the deficiency in which children present with different ocular symptoms including blindness. Malnourished children have an increased risk of developing this deficiency. Most of these children develop xerophthalmia, keratomalacia and other complications. A major part of the population in these countries also show subclinical form of VAD, where in vision in the dark is considerably affected.
As per the recent estimate by WHO, prevalence of VAD (as measured by the presence of night blindness in preschool children) is of moderate to severe public health significance in 122 countries [4]. The report also shows that about a third of the children in the preschool age is vitamin A deficient. An approximate number of 250,000 children become blind because of this nutrient deficiency. Improving the dietary intake of vitamin A or through supplements reduce the risk of complications and mortality [1]. A survey conducted by US Centers for Disease Control and Prevention showed that males had a better intake of the vitamin when compared to females. The level of intake varied considerably among the different ethnic groups in the country [5].
Pathophysiology
Retinoids and carotenoids are converted into retinyl esters which are absorbed from the intestine and transported to the liver for storage. About 80% of vitamin A in the body is stored in the liver in the form of hepatic retinol binding protein (RBP). The rest is stored in other regions like adipose tissue, lungs and kidneys. When the need arises, these retinyl esters undergo de-esterification and are transported to peripheral tissue region where they are taken up.
The body homeostatically maintains a small retinol concentration in the serum (40-50 mcg/dL). This serum concentration of retinol is indicative of the vitamin A levels in the body. When the store of vitamin A in different regions drops considerably, the serum level also shows a decline. A number of factors affect the measure of retinol in serum including infections, dietary intake of vitamin A, level of nutrients like zinc and iron, and synthesis of RBP in the liver [6].
Deficiency of zinc affects the synthesis of RBP and the impaired protein in turn affects the transportation of retinyl esters from their point of storage to peripheral tissues. Absorption of carotenoids depends on the source. Human body absorbs only about 60% of the plant carotenoids while it is able to absorb about 80-90% of retinyl esters from animal sources. Deficiency of nutrients like zinc and proteins also determine the level of carotenoid absorption. Gastrointestinal diseases and conditions that affect the absorption of fat will ultimately affect the absorption of vitamin A as it is fat-soluble. Diseases like cystic fibrosis, pancreatic insufficiency, and inflammatory bowel disease may all affect the level of serum retinol concentration. Alcohol consumption affects the metabolism of retinol by hindering the conversion of retinol to retinoic acid.
Prevention
Having a well-balanced diet is the most appropriate preventive measure for VAD. Including 4-5 servings of vegetables and fruits in the diet helps to provide a good supply of carotenoids and other provitamins. Opt for more of fortified foods like cereals, cereal-bars, and crackers to improve the quality of food. Include more animal sources of vitamin A like beef, chicken, egg yolk, whole milk, and liver. Green leafy vegetables, and colored fruits like oranges and mangoes are also good sources of vitamin A that provide sufficient amounts of carotenoids.
Summary
Vitamin A deficiency or VAD is a major micronutrient deficiency affecting millions of people worldwide, especially in the developing countries. Vitamin A, one of the first fat-soluble vitamins to be discovered, is essential for many physiological functions including vision, reproduction, growth and maintenance of epithelial layer, immunity, and growth of bones. They also play an important role in embryonic development and regulation of gene expression and differentiation in adults. Deficiency of this vitamin is one of the leading causes of visual impairment in children and is prevalent in more than 75 countries in the world. Vitamin A deficiency increases the chance of mortality and diseases in children. This condition is preventable and implementing timely and appropriate measures can considerably reduce mortality among children [1].
Patient Information
Vitamin A deficiency is caused by insufficient intake of vitamin A in the diet. It results in a number of complications like night blindness, dryness of the eyes, reduced immunity, loss of vision, and if not treated, it may even lead to death. Vitamin A deficiency is more prevalent in developing countries like Africa and South East Asia. It is more common among young children and pregnant women as their requirement for vitamins are more than normal. It is one of the leading cause of blindness in children worldwide.
One of the earliest symptoms of vitamin A deficiency is the difficulty to see in the dark, called night blindness. The eye finds it difficult to adjust the vision when the light is less. Conjunctiva, the transparent covering of white of the eye, may dry in severe cases of this deficiency. When left unattended, it may also lead to development of ulcers in the cornea. This may further result in loss of vision which is permanent.
Doctors may suggest an eye examination and evaluation of medical history to diagnose the condition. Laboratory tests to measure the amount of vitamin A in the serum is also recommended. In many cases, presence of night blindness is used as the most common indicator of this condition.
Mild and moderate forms of vitamin A deficiency is treated by a change in the diet. Including more of vitamin A-rich foods like vegetables and fruits, and vitamin-fortified foods like cereals and bread helps in improving the vitamin level in the body. Severe form of deficiency is treated using oral supplements of vitamin A. The dosage of these supplements depends on the age. In most of the cases the condition can be reversed with appropriate measures like diet and supplements. But if blindness has progressed, it would be difficult to bring it back to normal again. Including up to 5 servings of vegetables and fruits to increase the intake of vitamins and other nutrients helps to prevent this deficiency.
References
- Sommer A, West K. Vitamin A Deficiency. New York: Oxford University Press; 1996.
- Reddy V. History of the International Vitamin A Consultative Group 1975-2000. J Nutr. 2002;132(9 ):2852S-2856S.
- West K, Mehra S. Vitamin A Intake and Status in Populations Facing Economic Stress. Journal of Nutrition. 2009;140(1):201S-207S.
- World Health Organization. Global Prevalence Of Vitamin A Deficiency In Populations At Risk 1995-2005 WHO Global Database On Vitamin A Deficiency. Geneva: World Health Organization; 2009:3-55.
- Centers for Disease Control and Prevention. Dietary Intake Of Vitamins, Minerals, And Fiber Of Persons Ages 2 Months And Over In The United States: Third National Health And Nutrition Examination Survey, Phase 1, 1988-91. Maryland: National Center for Health Statistics; 1994.
- Munoz EC, Rosado JL, Lopez P. Iron and zinc supplementation improves indicators of vitamin A status of Mexican preschoolers. Am J Clin Nutr. 2000;71(3):789-794.
- Bhutta Z, Ahmed T, Black R et al. What works? Interventions for maternal and child undernutrition and survival. The Lancet. 2008;371(9610):417-440.
- Russell R. The vitamin A spectrum: from deficiency to toxicity. Am J Clin Nutr. 2000;71(4):878-884.
- Mayo-Wilson E, Imdad A, Herzer K, Yakoob M, Bhutta Z. Vitamin A supplements for preventing mortality, illness, and blindness in children aged under 5: systematic review and meta-analysis. BMJ. 2011;343.