Understanding What Deficiencies of Vitamins ADE and K Results From

December 8, 2025 •

5 min read

Over one billion people worldwide suffer from vitamin D deficiency, one of the four fat-soluble vitamins crucial for health. Deficiencies of vitamins ADE and K results from a variety of factors, including inadequate diet, malabsorption issues, and underlying medical conditions that interfere with their uptake and use by the body.

Quick Summary

Deficiencies of the fat-soluble vitamins A, D, E, and K are primarily caused by insufficient dietary intake, fat malabsorption disorders, certain chronic illnesses affecting the liver and digestive system, and specific medications.

Key Points

Malabsorption is a primary cause: Digestive disorders like cystic fibrosis, celiac disease, and Crohn's disease disrupt fat absorption, preventing the body from properly taking in fat-soluble vitamins A, D, E, and K.
Dietary intake plays a major role: Insufficient consumption of vitamin-rich foods or following a very low-fat diet can lead to deficiencies, especially for vitamin A in developing regions and vitamin E universally.
Limited sun exposure causes vitamin D deficiency: Since the body synthesizes vitamin D from sunlight, factors such as high latitude living, excessive sun protection, or being institutionalized can cause a shortage.
Medications and chronic illnesses interfere: Certain drugs (e.g., antibiotics, anti-seizure meds) and conditions like liver disease or chronic kidney disease can impair the metabolism, storage, or utilization of fat-soluble vitamins.
Newborns are at risk: Due to low placental transfer and a sterile gut at birth, infants are particularly susceptible to vitamin K deficiency, which is why prophylactic injections are common.
Fat is essential for absorption: All fat-soluble vitamins require dietary fat to be absorbed into the bloodstream. Conditions that inhibit fat digestion or are managed with low-fat diets can have systemic effects on these vitamins.

Introduction to Fat-Soluble Vitamin Deficiencies

Deficiencies in the fat-soluble vitamins A, D, E, and K can have significant health impacts, as these nutrients are vital for vision, bone health, immune function, and blood clotting. Unlike water-soluble vitamins, fat-soluble vitamins require dietary fat to be properly absorbed into the body from the small intestine. This unique absorption process means that conditions affecting fat digestion and absorption are primary causes of ADEK deficiencies. While inadequate dietary intake is a major factor globally, particularly in developing regions, malabsorption syndromes are the most common cause in developed countries.

Primary Causes: Malabsorption and Medical Conditions

Malabsorption is the inadequate assimilation of dietary substances, including fat-soluble vitamins. Any condition that interferes with the digestion and absorption of fats can lead to deficiencies in vitamins A, D, E, and K. Several medical conditions are known to cause malabsorption:

Cystic Fibrosis: This genetic disorder causes thick, sticky mucus to block the ducts of the pancreas, preventing pancreatic enzymes necessary for fat digestion from reaching the small intestine.
Celiac Disease: An autoimmune disorder triggered by gluten, it damages the villi lining the small intestine, which are responsible for nutrient absorption.
Chronic Pancreatitis: The pancreas becomes permanently damaged, leading to a loss of exocrine function and insufficient production of fat-digesting enzymes.
Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease and ulcerative colitis cause chronic inflammation of the digestive tract, which can impair nutrient absorption, especially if the small intestine is affected.
Liver and Biliary Diseases: The liver produces bile, and the gallbladder stores it, to help digest fats. Conditions such as cirrhosis, primary biliary cirrhosis, or bile duct obstruction reduce the availability of bile salts, leading to fat malabsorption.
Weight-Loss Surgery: Bariatric procedures like gastric bypass intentionally reduce the size of the stomach and/or reroute the small intestine, which significantly impacts nutrient and fat absorption.

Secondary Causes: Dietary and Lifestyle Factors

Beyond underlying medical conditions, other factors contribute to ADEK deficiencies:

Insufficient Dietary Intake: A diet low in fat and sources of vitamins A, D, E, and K is a straightforward cause. This is especially prevalent in resource-poor areas or for individuals following restrictive diets, including very low-fat diets.
Limited Sun Exposure: Vitamin D is synthesized by the skin upon exposure to ultraviolet-B (UVB) radiation from sunlight. Lack of sun exposure, due to factors like living at high latitudes, wearing covering clothing, using sunscreen, or being institutionalized, is a common cause of vitamin D deficiency.
Medications: Certain drugs can interfere with the absorption or metabolism of fat-soluble vitamins. Examples include broad-spectrum antibiotics, which can disrupt gut bacteria responsible for synthesizing some vitamin K, and some cholesterol-lowering and anti-seizure medications.
Age-Related Factors: The elderly and infants are particularly vulnerable. Older adults may have decreased sun exposure and reduced vitamin D production in their skin, while exclusively breastfed infants may not receive enough vitamin K and D, as breast milk has low levels.

Comparison of Fat-Soluble Vitamin Deficiency Causes


Cause Category	Vitamin A	Vitamin D	Vitamin E	Vitamin K
Malabsorption	Severe fat malabsorption, cystic fibrosis, celiac disease, liver disease	Malabsorption syndromes, cystic fibrosis, Crohn's, celiac disease	Liver disorders, gallbladder disorders, cystic fibrosis	Celiac disease, Crohn's, cystic fibrosis, liver disease
Dietary	Low intake of animal sources (retinol) and plant sources (carotenoids)	Insufficient intake from fortified foods and fatty fish	Very low-fat diet, inadequate intake	Insufficient intake of leafy greens, fermented foods
Lifestyle/Environment	Common in developing countries due to food insecurity	Lack of sun exposure (elderly, dark skin, high latitudes)	Extremely rare unless tied to malabsorption	Antibiotic use affecting gut bacteria
Other	Alcoholism, specific parasitic infections	Chronic kidney disease, obesity, certain medications	Rare genetic disorders affecting metabolism	Neonatal deficiency (low placental transfer, sterile gut)

Signs and Consequences of Deficiencies

Each fat-soluble vitamin plays a unique role, and its deficiency presents specific signs:

Vitamin A: Night blindness is often the first symptom. As the deficiency progresses, it can lead to dry eyes (xerophthalmia) and, if untreated, permanent blindness. Impaired immune function and susceptibility to infections are also common.
Vitamin D: Deficiency primarily affects bone health, causing rickets in children (bowing of the legs) and osteomalacia in adults (soft bones, muscle weakness, and pain). It is also associated with increased fracture risk and potential links to other chronic diseases.
Vitamin E: Deficiency is rare and typically linked to malabsorption or genetic disorders. Symptoms often include neurological issues, such as nerve damage, muscle weakness, vision problems, and impaired coordination.
Vitamin K: A lack of this vitamin impairs blood clotting, leading to excessive bleeding and easy bruising. In newborns, it can cause severe bleeding within the first few days or weeks of life.

Diagnosis and Management

Diagnosing these deficiencies typically involves a combination of assessing clinical signs, reviewing dietary and medical history, and blood tests to measure vitamin levels. A detailed evaluation is necessary to identify the underlying cause, whether it's dietary, malabsorptive, or metabolic. Treatment focuses on addressing the root cause and providing vitamin supplementation. This may involve correcting malabsorption with enzyme therapy, managing the underlying disease, or modifying diet and lifestyle. Supplements can be administered orally, or for severe malabsorption, via injection. Regular monitoring is crucial to ensure levels are restored and maintained. For example, individuals with malabsorption may require significantly higher daily doses of vitamin D than the general population.

Conclusion

Deficiencies of vitamins ADE and K results from a complex interplay of dietary insufficiency, impaired fat absorption due to chronic disease, and certain medications. As fat-soluble vitamins, their absorption is uniquely dependent on the presence of dietary fats, making conditions like cystic fibrosis, celiac disease, and liver disorders key culprits for deficiencies in developed countries. Recognizing the specific causes and resulting symptoms, from night blindness (A) and bone issues (D) to neurological problems (E) and bleeding (K), is essential for effective diagnosis and management. Proper treatment requires addressing the underlying cause and can often be achieved with targeted supplementation and dietary changes, restoring these vital nutrients and preventing long-term health complications. For more in-depth medical information on fat-soluble vitamin absorption, consult the article on the National Institutes of Health website.

Frequently Asked Questions

Malabsorption causes deficiencies because vitamins A, D, E, and K are fat-soluble, meaning they require dietary fat for proper absorption in the small intestine. Conditions that disrupt fat digestion or absorption, such as cystic fibrosis, celiac disease, or chronic pancreatitis, lead to the malabsorption of fats and, consequently, these essential vitamins.

Certain medications, such as broad-spectrum antibiotics, cholesterol-lowering drugs, and anti-seizure medications, can interfere with the body's absorption, metabolism, or production of fat-soluble vitamins. For example, antibiotics can disrupt gut bacteria that synthesize some vitamin K.

A poorly planned vegetarian or vegan diet can lead to deficiencies if not supplemented correctly. Preformed vitamin A (retinol) is found exclusively in animal products, while vitamin D is primarily found in fortified foods and fatty fish. Vitamin K2 is also more common in animal and fermented foods. Therefore, careful planning is necessary to ensure adequate intake from plant sources or supplements.

Sunlight exposure is a crucial factor for vitamin D levels. The body produces vitamin D when the skin is exposed to UVB rays. Insufficient sun exposure, due to lifestyle, location, or skin tone, is a major cause of vitamin D deficiency, as dietary sources alone are often insufficient.

Newborns are susceptible to vitamin K deficiency because only small amounts cross the placenta, breast milk contains low levels, and their intestines are not yet populated with the bacteria that produce vitamin K. This can cause a serious bleeding disorder if not managed with a prophylactic vitamin K injection at birth.

The first signs vary by vitamin. For vitamin A, it is often night blindness. For vitamin D, it may be bone pain and muscle weakness. Vitamin E deficiency is rare but may first present with subtle neurological symptoms. Vitamin K deficiency initially presents as easy bruising and excessive bleeding.

Diagnosis involves clinical assessment, evaluation of medical and dietary history, and measuring vitamin levels through blood tests. Treatment focuses on addressing the underlying cause and supplementing the deficient vitamin, which may require oral, or in severe cases, injectable forms. Regular monitoring is essential to ensure a successful outcome.