Introduction
In the area of human nutrition, micronutrients (vitamins and minerals) are considered important for maintaining optimal health and well-being. Vitamins are organic compounds that are classified as fat (vitamins A, D, E and K) or water-soluble (Vitamin C and B-complex such as B6, B9 and B12).1 Vitamins play an important role in a variety of processes required for the normal functioning of the body.
Vitamins serve as essential catalysts, assisting with the conversion of food into energy, boosting immune function, and assisting in cellular growth and restoration.2 Their importance extends to strengthening bones, maintaining healthy skin, and improving cognitive functions. For instance, a shortage of Vitamin D can weaken bones and increase the chances of bone fractures.
A deficiency in Vitamin C may give rise to scurvy, which can cause fatigue and bleeding gums. Such deficiencies can compromise bodily functions and significantly affect overall health, demonstrating the importance of maintaining a balanced and vitamin-rich diet to protect against these potential health setbacks.3 Our body cannot make the essential micronutrients either at all or in the required amount, so it is important to include them as part of a balanced diet.4
Types of vitamins
There are 9 water-soluble and 4 fat-soluble vitamins in the human body.4
A. Water-soluble vitamins
These types of vitamins are removed from the body through urine as they can easily dissolve in water. Therefore, it is important to maintain an adequate amount of these vitamins in the body through eating balanced meals or taking supplements.
1. Vitamin C
According to the National Institute of Health, vitamin C–
- Helps in controlling infections
- Acts as a powerful antioxidant that can neutralize harmful free radicals and might help prevent or delay the development of certain cancers and cardiovascular diseases
- Helps to make collagen (fibrous protein in connective tissue) that helps in wound healing
- Helps in the formation of hormones and chemical messengers used in the brain
- Helps in boosting immune function
2. B-vitamins (B1, B2, B3, B6, B9, B12, biotin, pantothenic acid)5
Vitamin | Function |
Thiamine (B1) | Helps convert food into energy and supports nerve function. |
Riboflavin (B2) | Plays a role in energy production and acts as an antioxidant to protect cells. |
Niacin (B3) | Aids in energy metabolism, promote healthy skin and supports digestion. |
Pantothenic Acid (B5) | It is part of coenzyme A, essential for various energy-related processes. |
Pyridoxine (B6) | Assists in amino acid metabolism and the production of neurotransmitters. |
Biotin (B7) | Supports metabolic processes and skin health and contributes to healthy hair. |
Folate (B9) | Vital for DNA synthesis, cell division, and growth. |
Cobalamin (B12) | Essential for nerve function and DNA synthesis, particularly in red blood cells. |
B. Fat-soluble vitamins
These vitamins (A, D, E, and K) are absorbed through a specialized process in the small intestine cells with the help of lipids (fats). Once absorbed, the vitamins are transported through the lymphatic system into the bloodstream. Excess consumption of fat-soluble vitamins can lead to toxicity since they are stored in the body's tissues and organs for a long time.5
1. Vitamin A
It is helpful in–6
- Cell division
- Organ and skeletal growth
- Allowing the immune system to function properly
- the development and maintenance of eye health and night vision
There are two types of vitamins A–3
- Preformed vitamin A - This type is called retinoids, which can include retinol, retinal and retinoic acid. It can be found in animal sources
- Provitamin A - These are converted to vitamin A in the body. It can be found in fruits, vegetables and other plant products
2. Vitamin D
It is helpful in–3
- Absorbing and retaining calcium and phosphorus in the body, which are needed for building bones
- Reducing cancer cell growth
- Controlling infections
- Reducing inflammations
3. Vitamin E
- The form of vitamin E that is utilized by the body is known as Alpha-tocopherol
- It acts as an antioxidant that neutralizes free radicals
- It enhances immune function and prevents the formation of blood clots in arteries3
4. Vitamin K
Vitamin K can be found in two forms–3
- Phylloquinone - This can be found in green, leafy vegetables
- Menaquinone - This can be found in animals and fermented foods. This form can be produced in the body with the help of certain bacteria
According to NHS, vitamin K helps in–
- Blood clotting
- Building bones
- Wound healing
Vitamin deficiency diseases
Vitamin deficiency is also known as hypovitaminosis which can be classified as primary or secondary. Primary hypovitaminosis is a condition in which the diet consumed cannot provide the required daily intake levels of vitamins. This can happen if people have a specific diet type that lacks certain types of micronutrients, such as in a vegan diet. Secondary hypovitaminosis is a condition caused by certain diseases such as Celiac, Crohn’s or chronic kidney disease that prevents the absorption of vitamins.2
According to the NHS, there is a recommended dose of vitamins that should be consumed with the help of a balanced diet. If this limit is exceeded, toxicity levels may have negative health impacts on the body.
These limits are for adults aged 19 to 64.
Vitamin | Recommended dose(mg) per day | Upper limit (Toxic) (mg) | |
Men | Women | ||
Vitamin A | 0.7 | 0.6 | 1.5 |
Vitamin B | |||
Vitamin B1 (Thiamine) | 1 | 0.8 | >100 |
Vitamin B2 (Riboflavin) | 1.3 | 1.1 | >40 |
Vitamin B3 (Niacin) | 16.5 | 13.2 | >17 nicotinic acid supplements or >500 nicotinamide supplements |
Vitamin B5 | No evidence | No evidence | >200 |
Vitamin B6 | 1.4 | 1.2 | >200 |
Vitamin B7 (Biotin) | No evidence | No evidence | >0.9 |
Vitamin B12 | 1.5 | 1.5 | No evidence |
Vitamin C | 40 | 40 | >1000 |
Vitamin D | 0.015 | 0.015 | >0.1 |
Vitamin E | 4 | 3 | >540 |
Vitamin K | 0.001 for each kg body weight | No evidence |
1. Vitamin C deficiency: Scurvy
A severe (less than 10 mg daily one month or longer) vitamin C deficiency is called scurvy. It is very rare and can be treated easily.3
Signs of vitamin C deficiency (NIH)–
- Fatigue
- Inflammation/bleeding of gums
- Joint pain
- Poor wound healing
- Iron deficiency anaemia
- Skin spots
Groups at higher risk (NHS)–
- No intake of fresh fruits and vegetables for a long period
- Chronic smokers
- People dependent on drugs or alcohol
- Pregnant or breastfeeding women with poor diet
- Chronic diseases e.g. renal dialysis
2. B-vitamin deficiencies
a. B1 deficiency: Beriberi
In early stages, it causes (NIH)–
- Weight loss
- Confusion
- Memory loss
- Muscle weakness
With chronic alcohol consumption, it causes Wernicke-Korsakoff syndrome.3
Groups at higher risk (NIH) –
- People who consume alcohol chronically
- People with HIV/AIDS
- People with diabetes
- People who have undergone bariatric surgery
b. B2 deficiency: Ariboflavinosis
Symptoms can include–3
- Skin disorders
- Swelling of mouth and throat
- Cracked lips
- Swollen tongue
- Hair loss
Groups at higher risk (NIH)–
- People who eat a vegan diet or consume less milk
- Pregnant and lactating women
c. B3 deficiency: Pellagra
Symptoms can include (NIH)–
- Pigmented rash or brown discoloured skin when exposed to sunlight
- Bright red tongue
- Depression
- Fatigue
- Memory loss
Groups at higher risk –3
- Undernutrition people
- People who consume alcohol chronically
- People with neuroendocrine tumours
d. B6 deficiency: Anemia, neurological issues
Symptoms can include–3
- Microcytic anaemia
- Scaling on the corner of mouth and lips
- Swollen tongue
- Weak immune system
- Depression
Groups at higher risk (NIH)–
- People who have Chronic alcohol dependence
- People with Poor kidney function
- People with autoimmune diseases
e. B7 deficiency: Biotin deficiency
Symptoms can include–3
- Thinning hair
- Scaly, red rash around eyes, mouth and nose
- Brittle nails
Groups at higher risk (NIH)–
- People with biotinidase deficiency
- People who consume alcohol chronically
- Pregnant and breastfeeding women
f. B9 deficiency: Neural tube defects, anaemia
Symptoms can include (NIH)–
- Weakness and fatigue
- Difficulty in concentrating
- Headache
- Shortness of breath
Groups at higher risk–
- People who consume alcohol chronically
- Women of childbearing age and pregnant women
- People With malabsorptive disorder such as celiac disease and inflammatory bowel disease
g. B12 deficiency: Pernicious anaemia, nerve damage
Symptoms can include–3
- Megaloblastic (a condition where larger-than-normal sized red blood cells are present only in small amount) or pernicious anaemia (a type of megaloblastic anaemia in which vitamin B12 is not absorbed)
- Fatigue
- Memory loss
- Depression
- Seizures
Groups at higher risk–
- Vegetarians
- Infants of women with vegan diet
- People who underwent gastrointestinal surgery
3. Vitamin A deficiency: Xeropthalmia
Symptoms can include–3
- Severe blindness of the eye
- Night blindness
- Dry skin or hair
Groups at higher risk (NIH)–
- Premature infants
- People suffering from cystic fibrosis
- People with gastrointestinal disorder
4. Vitamin D deficiency: Rickets (in children), osteomalacia (in adults)
Symptoms can include (NIH)–
- Bone deformities
- Hypocalcemic seizures (seizures caused by low calcium levels)
- Tetanic spasm
- Dental abnormalities
Groups at higher risk–7
- Breastfed infants
- People with limited sun exposure
- People with darker skin complexion
- People with conditions that limit fat absorption
- People who are obese
- People who have undergone gastric bypass surgery
5. Vitamin E deficiency
This is rare but premature babies whose birth weight is very low (<1,500 grams) might be deficient in vitamin E. (NIH)
Symptoms can include–3
- Retinopathy (damage to the retina of eyes that can impair vision)
- Peripheral neuropathy (damage to peripheral nerves causing weakness and pain in hands or feet)
- Ataxia (loss of control of body movements)
- Decreased immune function
Groups at higher risk–3
- People with Fat malabsorption diseases
6. Vitamin K deficiency
Symptoms can include– 3
- Prolonged bleeding
- Bleeding
- Haemorrhaging
- Osteoporosis
Groups at higher risk (NIH)–
- Newborns not treated with vitamin K at birth
- People with malabsorption disorders
Prevention and treatment
Preventing and treating vitamin deficiency diseases depends on a multi-directional approach. A balanced diet, enriched with diverse nutrient sources, forms the foundation of prevention. Dietary adjustments and supplementation can aid in addressing mild deficiencies, but medical interventions become crucial for severe cases.
Educating individuals about the importance of maintaining a well-rounded diet and seeking professional guidance ensures that vitamin deficiencies are tackled effectively, promoting long-term health and vitality.8
According to NHS, these food sources should be a part of a balanced diet to avoid vitamin deficiency in the body.
Vitamin | Food sources |
Vitamin A | Cheese, eggs, oily fish, milk, yoghurt |
Vitamin B | |
Vitamin B1 (Thiamine) | Peas, nuts, whole grain bread, banana, orange |
Vitamin B2 (Riboflavin) | Milk, eggs, mushrooms, yoghurt |
Vitamin B3 (Niacin) | Meat, fish, wheat flour, eggs |
Vitamin B5 (Pantothenic acid) | Chicken, beef, eggs, mushroom, avocado |
Vitamin B6 | Pork, chicken, peanut, soybean, oats, banana, milk |
Vitamin B7 (Biotin) | Beef liver, egg, salmon, sweet potato, almonds (NIH) |
Vitamin B12 | Meat, fish, eggs, milk, cheese |
Vitamin C | Citrus fruits e,g, oranges, peppers, strawberries, blackcurrant, broccoli, potatoes |
Vitamin D | Oily fish such as salmon, mackerel, sardines and herring, red meat, liver, egg yolk |
Vitamin E | Plant oils such as rapeseed, sunflower, soya, corn and olive oil. Nuts and seeds. |
Vitamin K | Green leafy vegetables such as broccoli and spinach, vegetable oils and cereal grains |
FAQ
What are the diseases caused by vitamin deficiency?
Vitamin deficiencies can lead to various diseases. For instance, a lack of vitamin D causes rickets, vitamin C deficiency causes scurvy and vitamin A deficiency causes night blindness. Inadequate B vitamins may cause anaemia. Proper nutrition is essential to prevent these ailments.
What are three common vitamin deficiencies?
Three common vitamin deficiencies are
a. Vitamin D deficiency, linked to weak bones, immune system issues, and fatigue.
b. Vitamin B12 deficiency causes anaemia, fatigue, and neurological problems.
c. Vitamin C deficiency leads to weakened immunity, skin issues, and slower wound healing. A balanced diet and supplements can help prevent these deficiencies.
How do you know if you have a vitamin deficiency?
Signs of a vitamin deficiency include fatigue, weakness, frequent infections and poor wound healing. Specific symptoms also include brittle hair/nails (biotin deficiency) or night blindness (vitamin A deficiency). Blood tests and consultation with a healthcare professional would be needed for an accurate diagnosis. Appropriate treatment can be achieved through dietary changes or consuming supplements.
What happens if your vitamin B12 is low?
Low vitamin B12 levels can lead to anaemia, causing fatigue, weakness, and pale skin. Neurological issues like numbness, tingling, and difficulty walking may also occur. If untreated, it can lead to irreversible nerve damage. Replenishing B12 through diet, supplements, or injections is crucial to prevent and manage these symptoms.
Summary
Vitamin deficiency diseases result from inadequate intake or absorption of essential vitamins, leading to various health disorders affecting immune function, bone health, energy production, and more. Lack of specific vitamins can lead to conditions like scurvy (vitamin C deficiency), rickets (vitamin D deficiency), and anaemia (vitamin B12 deficiency). To prevent these ailments, maintaining a diet rich in fruits, vegetables, whole grains, lean proteins, and dairy is paramount.
If a person cannot adhere to a certain diet due to specific medical conditions, then supplements should be considered as an option.9 Public awareness and education about the importance of balanced nutrition are key to reducing vitamin deficiency-related health issues. By prioritizing adequate vitamin intake, individuals can pave the way for a healthier future.8
References
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- Brancaccio M, Mennitti C, Cesaro A, Fimiani F, Vano M, Gargiulo B, et al. The biological role of vitamins in athletes’ muscle, heart and microbiota. Int J Environ Res Public Health [Internet]. 2022 Jan 23 [cited 2023 Aug 28];19(3):1249. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8834970/
- Avenue 677 Huntington, Boston, Ma 02115. The Nutrition Source. 2012 [cited 2023 Aug 28]. Vitamins and minerals. Available from: https://www.hsph.harvard.edu/nutritionsource/vitamins/
- Godswill AG, Somtochukwu IV, Ikechukwu AO, Kate EC. Health benefits of micronutrients (Vitamins and minerals) and their associated deficiency diseases: a systematic review. International Journal of Food Sciences [Internet]. 2020 Jan 7 [cited 2023 Aug 28];3(1):1–32. Available from: https://www.iprjb.org/journals/index.php/IJF/article/view/1024
- Ofoedu CE, Iwouno JO, Ofoedu EO, Ogueke CC, Igwe VS, Agunwah IM, et al. Revisiting food-sourced vitamins for consumer diet and health needs: a perspective review, from vitamin classification, metabolic functions, absorption, utilization, to balancing nutritional requirements. PeerJ [Internet]. 2021 Sep 1 [cited 2023 Aug 28];9:e11940. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8418216/
- Hombali AS, Solon JA, Venkatesh BT, Nair NS, Peña‐Rosas JP. Fortification of staple foods with vitamin A for vitamin A deficiency. Cochrane Database Syst Rev [Internet]. 2019 May 10 [cited 2023 Aug 29];2019(5):CD010068. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6509778/
- Bilezikian JP, Formenti AM, Adler RA, Binkley N, Bouillon R, Lazaretti-Castro M, et al. Vitamin D: Dosing, levels, form, and route of administration: Does one approach fit all? Rev Endocr Metab Disord [Internet]. 2021 Dec 1 [cited 2023 Aug 29];22(4):1201–18. Available from: https://doi.org/10.1007/s11154-021-09693-7
- Darnton-Hill I. Public health aspects in the prevention and control of vitamin deficiencies. Curr Dev Nutr [Internet]. 2019 Jun 21 [cited 2023 Aug 29];3(9):nzz075. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6775441/
- Zhang FF, Barr SI, McNulty H, Li D, Blumberg JB. Health effects of vitamin and mineral supplements. BMJ [Internet]. 2020 Jun 29 [cited 2023 Aug 29];369:m2511. Available from: https://www.bmj.com/content/369/bmj.m2511