Symptoms related to fat-soluble vitamin deficiency do depend on the severity of the deficiency itself; in cases where a mild insufficiency is present, symptoms may be absent or too mild to observe. Profound FSV deficiency typically leads to a plethora of clinical symptoms and can even threaten an individual's life.

Vitamin A

Patients with vitamin A deficiency typically report night blindness and xerophthalmia [1] [2]. Bitot's spots may be visible due to a collection of keratin in the conjunctiva, and the observation of keratomalacia in pediatric patients requires immediate therapeutic intervention as a medical emergency [3]. Children presenting with vitamin A deficiency also display growth delays and may present with an active infection pertaining to the respiratory, gastrointestinal tract or other systems. Patients may also present with infertility and spontaneous abortions without apparent underlying gynecological pathology, dry skin with hyperkeratotic lesions and dry hair [4]. Vitamin A deficiency also results in anemia, in which case the individual may present with weakness, fatigue and, possibly, pallor.

Vitamin D

Vitamin D deficiency is known to cause rickets in children. Pediatric patients affected by rickets present with osphyalgia, pelvic pain or pain the legs, muscle weakness and skeletal deformities, such as:

• Bow knees or knock-knees
• Kyphoscoliosis
• Sternal deformities
• Rachitic rosary appearance of the ribs
• Thickened skull bone
• Craniotabes

Amongst the adult population, vitamin D deficiency is primarily responsible for causing osteomalacia and osteoporosis [1]; patients tend to present with fractures caused by mild forces or even spontaneous fractures as well as muscle hypotonia and persisting pain [5]

Vitamin E

Patients with decreased vitamin E serum levels present with neurological symptoms, such as ataxia, similar to Friedrich's ataxia [6] [7] [8] [9] [10]. Additional symptoms may include muscle hypotonia, a limited visual field or complete loss of vision, cardiac dysrhythmia and dementia.

Vitamin K

The predominant symptom of vitamin K deficiency is hemorrhage which can be observed in any region of the body; petechiae, easy and frequent bruising, hematomas, hematuria or constant bleeding that does not respond to the standard pressure [11]. Infants may also display an incomplete facial, nasal or skeletal development or present with epileptic activity, anemia, vomiting and mucosal bleeding, due to atraumatic intracranial hemorrhaging.

• Fatigue

  Vitamin A deficiency also results in anemia, in which case the individual may present with weakness, fatigue and, possibly, pallor. Vitamin D Vitamin D deficiency is known to cause rickets in children. [symptoma.com]

  Also Read: 9 Amazing Health Benefits of Vitamin D Signs and Symptoms of Vitamin D Deficiency Muscle pain Tiredness and fatigue Depression and anxiety Poor bone health and bone loss Read in Detail Here: Vitamin D Deficiency Symptoms Dietary Sources of [ayurtimes.com]

  Deficiency more often due to poor absorption than low consumption Meat, seafood, eggs, and dairy C (ascorbic acid): Antioxidant 7.1% 31% Scurvy, fatigue, anemia, joint pain, petechia. [mdedge.com]

  The nervous and muscular system may also be affected, causing symptoms such as loss of appetite, irritability, fatigue, insomnia, restlessness, headache and muscle weakness. [food-info.net]

  Signs of a thyroid issue, like weight gain, an inability to lose weight, and fatigue, may be a sign to have your levels of iodine and vitamin A checked. [wwws.fitnessrepublic.com]

• Malnutrition

  They are more commonly diagnosed in infants and children and can be caused either by conditions interfering with the absorption of fat, chronic conditions, cholestasis or, in adults, malnutrition. [symptoma.com]

  In addition, about 1 in 5 patients suffers from malnutrition, with most of those showing involuntary weight loss and a low BMI. [glutenfreetherapeutics.com]

  These vitamins also play an important role in Protein Energy Malnutrition [PEM]. The level of vitamin A and E decreases in these children and thus supplementation becomes a priority for all the PEM cases. [completewellbeing.com]

  In the 1960s, the World Health Organization (WHO) undertook the first global survey of VAD with associated xerophthalmia and complicated measles. [6] In 1973, an international vitamin A board was set up to alleviate global malnutrition. [emedicine.medscape.com]

  It most commonly occurs in developing nations usually due to malnutrition. Since vitamin A is stored in the liver, it may take up to 2 years for signs of deficiency to appear. [extension.colostate.edu]

• Plethora

  Profound FSV deficiency typically leads to a plethora of clinical symptoms and can even threaten an individual's life. Vitamin A Patients with vitamin A deficiency typically report night blindness and xerophthalmia. [symptoma.com]

• Hunting

  Koletzko B, Goulet O, Hunt J, et al. [journals.lww.com]

• Internal Bleeding

  The most talked about are Vitamin D and K, so much so that pediatricians are now recommending supplementing infants, and giving newborns Vitamin K vaccines to prevent deadly issues with internal bleeding. YIKES! [sacredvesselacupuncture.com]

• Rachitic Rosary

  Pediatric patients affected by rickets present with osphyalgia, pelvic pain or pain the legs, muscle weakness and skeletal deformities, such as: Bow knees or knock-knees Kyphoscoliosis Sternal deformities Rachitic rosary appearance of the ribs Thickened [symptoma.com]

• Muscle Hypotonia

  Additional symptoms may include muscle hypotonia, a limited visual field or complete loss of vision, cardiac dysrhythmia and dementia. [symptoma.com]

• Pelvic Pain

  Pediatric patients affected by rickets present with osphyalgia, pelvic pain or pain the legs, muscle weakness and skeletal deformities, such as: Bow knees or knock-knees Kyphoscoliosis Sternal deformities Rachitic rosary appearance of the ribs Thickened [symptoma.com]

Vitamin A levels in a symptomatic patient can be directly measured via a high-performance liquid chromatography serum retinol study. A concentration lower than 0.7 mg/L in patients under the age of 12 years is deemed pathologically low [12]. A serum RBP study can also be used to approximately evaluate the adequacy of vitamin A in the serum, but its accuracy is lower [13] [14]. The complete laboratory assessment for a potential vitamin A deficiency also includes an iron panel, biochemical profile, zinc and albumin levels and a complete blood count.

With reference to vitamin K, its suspected deficiency can be diagnosed by measuring des-gamma-carboxy prothrombin (DCP) in the serum, as it is a protein molecule which is known to be elevated in the absence of vitamin K and can be safely used as a marker of vitamin K deficiency and hemorrhage [15]. Serum phylloquinone can also be measured, although the results are not completely accurate; a concentration lower than 0.15 mcg/L implies a deficiency [16]. Patients with vitamin K deficiency also exhibit an increased serum prothrombin time (PT) and a normal activated partial thromboplastin time (aPTT) [17].

Furthermore, in order to measure the concentration of Vitamin E, serum alpha-tocopherol levels must be obtained. Individuals with hyperlipidemia are evaluated by calculating the alpha tocopherol to lipid ratio. Lastly, a potential vitamin D deficiency is diagnosed by measuring serum 25(OH)D concentration.

• Vitamin E Decreased

  Vitamin A interferes with absorption of vitamin K, and large doses of vitamin E decrease vitamin K–dependent clotting factors, thus promoting bleeding. [diet.com]

• Vitamin E Decreased

  Vitamin A interferes with absorption of vitamin K, and large doses of vitamin E decrease vitamin K–dependent clotting factors, thus promoting bleeding. [diet.com]

1. Plum LA, DeLuca HF. Vitamin D, disease and therapeutic opportunities. Nat Rev Drug Discov. 2010;9:941–55
2. Stephensen CB. Vitamin A, infection, and immune function. Annu Rev Nutr. 2001;21:167–92.
3. Blecker U, Mehta DI, duPont AI, Davis R, Sothern MS, Suskind RM. Fat-soluble Vitamin Deficiencies. Pediatrics in Review. Nov. 1999; Vol. 20/ Issue 11.
4. Harrison's Principles of Internal Medicine. 15th ed. New York, NY: McGraw-Hill; 2001. vol 1: 465-6.
5. Holick MF. Vitamin D deficiency: what a pain it is. Mayo Clin Proc. 2003 Dec;78(12):1457-9.
6. Benomar A, Yahyaoui M, Marzouki N, et al. Vitamin E deficiency ataxia associated with adenoma. J Neurol Sci. 1999 Jan 1; 162(1):97-101.
7. Sokol RJ. Vitamin E and neurologic deficits. Adv Pediatr. 1990; 37:119-48.
8. Sokol RJ, Guggenheim MA, Heubi JE, et al. Frequency and clinical progression of the vitamin E deficiency neurologic disorder in children with prolonged neonatal cholestasis. Am J Dis Child. 1985 Dec; 139(12):1211-5.
9. Tanyel MC, Mancano LD. Neurologic findings in vitamin E deficiency. Am Fam Physician. 1997 Jan; 55(1):197-201.
10. Rino Y, Suzuki Y, Kuroiwa Y, et al. Vitamin E malabsorption and neurological consequences after gastrectomy for gastric cancer. Hepatogastroenterology. 2007 Sep; 54(78):1858-61.
11. Lee GR, Bithell TC, Forester J. Acquired coagulation disorders. Wintrobe's Clinical Hematology. Baltimore, Md: Williams & Wilkins; 1993; 1473-80.
12. West KP Jr, Mehra S. Vitamin A intake and status in populations facing economic stress. J Nutr. 2010 Jan; 140(1):201S-7S.
13. de Pee S, Dary O. Biochemical indicators of vitamin A deficiency: serum retinol and serum retinol binding protein. J Nutr. 2002 Sep; 132(9 Suppl):2895S-901S.
14. Weinman AR, Jorge SM, Martins AR, et al. Assessment of vitamin A nutritional status in newborn preterm infants. Nutrition. 2007 Jun; 23(6):454-60.
15. Liebman HA, Furie BC, Tong MJ. Des-gamma-carboxy (abnormal) prothrombin as a serum marker of primary hepatocellular carcinoma. N Engl J Med. 1984 May 31;310(22):1427-31.
16. Martin J. Shearer, Xueyan Fu, Sarah L. Booth. Vitamin K Nutrition, Metabolism, and Requirement: Current Concept and Future Research. Advances in Nutrition. 2012; 3:182-195.
17. Krasinski SD, Russell RM, Furie BC. The prevalence of vitamin K deficiency in chronic gastrointestinal disorders. Am J Clin Nutr. 1985 Mar; 41(3):639-43.