The 26 Essential Vitamins and Minerals - Deficiencies and Toxicity

On this page we have outlined some of the problems that can occur if you don't get enough of the vitamins and minerals included in Huel in your daily diet or, in some cases, if you get too much of them by using supplements.

Vitamin A

Vitamin A is particularly important for healthy skin and eyes[2]. Vitamin A deficiency is the world’s leading cause of preventable blindness in children, and increases the risk of disease and death[1]. It’s a serious problem in more than half of all countries, though it mainly affects poorer regions[1].

In pregnant women, a deficiency can cause night blindness, and increase the risk of maternal mortality[1].

Vitamin D

Up to a quarter of the population have low levels of vitamin D in their blood according to UK government figures[3]. We can synthesise vitamin D from direct sunlight[4] so vitamin deficiency symptoms can be a particular issue during the autumn and winter months with fewer sunlight hours[4].

Vitamin D has several important functions. For example, it helps to regulate the amount of calcium and phosphate in the body[5].

A lack of vitamin D can lead to rickets in children and osteomalacia in adults, which is characterised by weakness, aches and pains because the bones don’t have enough calcium[3].

Vitamin E

You are unlikely to have a deficiency of vitamin E, as any excess is stored in your body naturally[6].

However, meeting the daily recommendations is important because it is an antioxidant. An antioxidant prevents oxidation and the subsequent damage it can cause, including protecting against free radicals[7].

Vitamin E is involved in maintaining healthy skin and regulating and strengthening the immune response[8].

Vitamin K

Vitamin K has several important functions, such as blood clotting, which means it helps wounds to heal properly[9]. It also works with vitamin D to regulate calcium in the body and so plays a role in bone health[9].

The body only needs a little vitamin K, so deficiencies are rare, but a healthy balanced diet is necessary to ensure you have enough[10].

Vitamin C

Vitamin C (or ascorbic acid) is vital because it’s needed to make collagen[12]. Without it, collagen can’t be replaced and the body’s tissues break down, leading to the signs and symptoms of scurvy[11]. These include muscle and joint pain, fatigue, red dots on the skin, and bleeding and swelling of the gums[13].

Vitamin C is also an antioxidant and regenerates other molecules such as vitamin E, so they can be used as antioxidants multiple times[12].

You’d have to take a lot of vitamin C from supplements to reach the safe upper limit, but very high levels over long periods of time may lead to kidney stones in at-risk individuals[14].


Thiamin (vitamin B1) is important for energy metabolism, particularly carbohydrate metabolism[15]. It’s also key for muscle contractions and the conduction of nerve signals[15].

Thiamin deficiency causes beriberi disease and can cause weakness, fatigue, psychosis and nerve damage[16].Whilst it’s not very common, alcoholics are most at risk of beriberi[16].


Riboflavin (vitamin B2) is also involved in energy metabolism. It keeps the skin, eyes and nervous system healthy[17].

Deficiency of riboflavin (ariboflavinosis) can cause several symptoms such as a sore throat, cheilosis (lesions on the lips), normocytic, normochromic anaemia, and angular stomatitis (lesions on the angles of the mouth)[18]. Without riboflavin, several other vitamins, such as folate, can’t be metabolised so riboflavin deficiency often occurs with other vitamin deficiencies[19].


Niacin (vitamin B3) is the general name for both nicotinic acid and nicotinamide/niacinamide.

Niacin is important for helping the body to release energy from the food sources we eat. It also ensures a proper functioning nervous system and liver[20].

Taking too much niacin is only possible from supplements, not food. If taken for too long at high doses, supplements can cause liver damage[21].

Vitamin B6

Vitamin B6 (or pyridoxine) is a group of six compounds. Vitamin B6 has a wide variety of functions and is particularly involved in protein metabolism[22]. It is a key component in the formation of haemoglobin (the substance in red blood cells that carries oxygen around the body)[23].

It's crucial for producing thyroid hormone alongside with iodine[24]. An overactive thyroid will require more vitamin B6, so muscle weakness is very common in people with this condition [A1] due to a lack of vitamin B6[24].

Long-term high doses of vitamin B6 can be toxic and may result in nerve damage. This can become irreversible if this occurs for more than a few months[23].


Folate, or folic acid (also known as vitamin B9), works with vitamin B12 to form healthy red blood cells[25]. Folate also helps to reduce the risk of central neural tube defects, such as spina bifida in unborn babies, which is why maintaining a healthy amount is important during pregnancy[26].

Because of its role in red blood cell formation, a deficiency can lead to folate deficiency anaemia, which causes tiredness, diarrhoea, loss of appetite, heart palpitations and behavioural disorders[27].

Vitamin B12

Vitamin B12 (or cobalamin) has similar roles to folate, helping make red blood cells and playing roles in brain health and DNA synthesis[28].

A lack of B12 can cause the same symptoms as folate deficiency leading to vitamin B12 deficiency anaemias, like pernicious anaemia[27].

Pantothenic Acid

Pantothenic acid is also known as vitamin B5. Like all the B vitamins, it's involved in releasing energy from food, particularly fatty acids[29].

A lack of pantothenic acid can cause fatigue, chronic stress and depression, although it’s difficult to determine the symptoms because it isn’t common and often occurs with other deficiencies[30].


Biotin (or Vitamin B7) is required for the metabolism of all three macronutrients[31]. Only small amounts are required in the diet as our gut microbiota can produce biotin for the body to use[32].


Choline may be a non-essential B vitamin, but it is important for cell membranes and for the production of the neurotransmitter acetylcholine, which has a role in memory and muscle control[33].

A lack of choline is unlikely, but it can cause muscle damage and non-alcoholic fatty liver disease (NAFLD)[34].


Potassium is a key electrolyte and so is important for controlling the balance of fluids in the body[35]. It also plays a critical role in nerve transmission and muscle contractions, particularly the heart[35].

Taking too much potassium from supplements can cause stomach pain and diarrhea. High potassium levels may also be the result of kidney disease[36].

Sodium & Chloride

Most chloride is gained from salt (sodium chloride), so deficiencies are rare. However, consuming too much salt is very common due to the abundance of salt in everyday food.

Sodium and chloride are electrolytes that help keep the level of fluids in the body balanced. Sodium also works with potassium in nerve transmissions[37], while chloride helps the body to digest food because it’s an essential component of the fluids in the stomach[38].

Consuming excessive amounts of salt is linked to an increase in blood pressure (hypertension), which raises your risk of having a stroke or heart attack[39].


Calcium is the most abundant mineral in our body as it’s a major constituent of bones and teeth.

Calcium is required for muscle contraction, and short-term deficiency may cause muscle cramps, stiffness and poor mobility[40].

It’s important to have a good intake in the bone-building years, which are as a baby and again from adolescence to about 30 years of age, especially for females[41]. Insufficient amounts can lead to brittle-bone disease (osteoporosis) when you’re older, where your bones break very easily due to the slow loss of bone mass[42].

Although calcium toxicity is rare, acute symptoms may include fatigue, muscle weakness, kidney stones and constipation, while long-term excessive calcium intake may increase the risk of developing several diseases[43]. Too much calcium can also limit iron absorption[44].


Phosphorus is a mineral that helps to build and maintain strong bones and teeth in conjunction with calcium[45]. Phosphorus also helps release energy from food[46].

Acute high doses of phosphorus supplements can cause diarrhea and stomach pain[45]. Taking high doses for a long time in the absence of adequate calcium intake can increase bone fracture risk[47].


Magnesium is important for energy regulation, muscle and, nerve function[48].

Taking high doses of magnesium for a short time can cause diarrhea, nausea, vomiting and abdominal cramping[49].


Iron is an essential mineral with several important roles in the body. Its most well-known role is as a key component of hemoglobin, which allows red blood cells to transport oxygen around the body[50].

Iron deficiency, which can lead to iron-deficiency anemia, is one of the most common micronutrient deficiencies globally[51]. It is a particular issue for menstruating women due to monthly blood loss[50].

Excessive iron intake in one sitting can cause constipation, nausea and vomiting, especially if food is not eaten at the same time[52].


Zinc plays roles in the immune system, including wound healing, and growth and development[53].

Zinc deficiency affects an estimated two billion people[54]. In children, this can cause growth retardation and an impaired immune system resulting in an increased risk of infections[53].

Taking high doses of zinc over a long period reduces the amount of copper that the body can absorb. This can lead to anemia and the weakening of bones[55].


Copper plays a vital role in the immune system through antioxidant defense and its involvement in white blood cell production[56]. It’s also needed for iron metabolism and, therefore, the formation of hemoglobin[57].

Both copper deficiency and toxicity are relatively rare[58]. Taking high doses of copper can cause stomach pain, diarrhea and nausea[57].


Manganese is a trace element that is involved in the metabolism of food to produce energy[59]. It also has pro- and antioxidant activities[60].

Manganese toxicity is partly attributable to its prooxidant activity, which can cause oxidative stress that the body can’t cope with[61]. Toxicity via ingestion is very rare compared to inhalation and is only likely to occur by consuming supplements over a long period of time[60].


Selenium is a trace element that plays an important role in our immune system’s function and is also a potent antioxidant helping to prevent damage to cells and tissues[62].

Too much selenium over a prolonged period causes selenosis. Symptoms can range from hair and nail loss to skin rashes and nervous system abnormalities[63].


Chromium is a trace element that appears to aid the action of insulin[64]. As a result, it’s important for carbohydrate metabolism and is thought to play a role in type 1 and type 2 diabetes[65].

The NHS reports there is not enough research to know for certain the long-term effects of excess chromium intake[66].


Molybdenum is a trace element that helps make and activate some of the enzymes involved in detoxification and repairing and making genetic material[67].

There is some evidence to suggest taking molybdenum supplements might cause joint pain although the toxicity of molybdenum appears to be relatively low[68].


Iodine is involved in the synthesis of thyroid hormones. These hormones control the body’s metabolism and ensure proper bone and brain development[69].

The first sign of iodine deficiency is often enlargement of the thyroid gland (goiter). This can progress to decreasing mental capacity and in children stunt growth and brain development[70].

Taking high doses of iodine for long periods of time can cause similar symptoms to iodine deficiency such as goiter. It can also cause weight gain and nausea[70].


For all the vitamins and minerals mentioned, Huel meets at least 100% of the recommended daily amount (RDA). Where amounts are higher than the RDA this is due to additional health benefits and/or to account for bioavailability. Bioavailability refers to how much of a particular nutrient is absorbed into the body from the gut. All the vitamins and minerals in Huel are also within safe upper limits.

Take a look at our About the Vitamins & Minerals in Huel and How Well are the Vitamins and Minerals in Huel Absorbed? articles for more information.


  1. WHO. Micronutrient deficiencies: Vitamin A deficiency. Date Accessed: 22/05/19. [Available from:]
  2. NHS. Vitamin A. Date Accessed: 22/05/19. [Available from:]
  3. SACN. Vitamin D and Health. London: 2016.
  4. NHS. Vitamin D. Date Accessed: 20/06/19. [Available from:]
  5. DeLuca HF. Overview of general physiologic features and functions of vitamin D. The American journal of clinical nutrition. 2004; 80(6):1689S-96S.
  6. NHS. Vitamin E. Date Accessed: 22/05/19. [Available from:]
  7. Lobo V, et al. Free radicals, antioxidants and functional foods: Impact on human health. Pharmacogn Rev. 2010; 4(8):118-26.
  8. Rizvi S, et al. The role of vitamin e in human health and some diseases. Sultan Qaboos Univ Med J. 2014; 14(2):e157-e65.
  9. Institute LP. Oregon State University. Vitamin K. Date Accessed: 22/05/19. [Available from:]
  10. NHS. Vitamin K. Date Accessed: 22/05/19. [Available from:]
  11. Cook GC. Scurvy in the British Mercantile Marine in the 19th century, and the contribution of the Seamen’s Hospital Society. Postgraduate Medical Journal. 2004; 80(942):224-9.
  12. Traber MG, et al. Vitamins C and E: beneficial effects from a mechanistic perspective. Free Radic Biol Med. 2011; 51(5):1000-13.
  13. NHS. Scurvy. Date Accessed: 22/05/19. [Available from:]
  14. Institute LP. Oregon State University. Vitamin C: Toxicity. Date Accessed: 22/05/19. [Available from:]
  15. Manzetti S, et al. Thiamin function, metabolism, uptake, and transport. Biochemistry. 2014; 53(5):821-35.
  16. KD W, et al. Vitamin B1 Thiamine Deficiency (Beriberi). Treasure Island (FL): StatPearls Publishing; 2019. Available from:
  17. NHS. Riboflavin. Date Accessed: 24/05/19. [Available from:]
  18. NHS: South Tees Hospitals. Vitamin B2 (Riboflavin). Date Accessed: 24/05/19.
  19. Institute LP. Oregon State University. Riboflavin. Date Accessed: 24/05/19. [Available from:]
  20. Meyer-Ficca M, et al. Niacin. Adv Nutr. 2016; 7(3):556-8.
  21. NHS. Niacin (Vitamin B3). Date Accessed: 24/05/19. [Available from:]
  22. NIH. Vitamin B6. Date Accessed: 24/05/19. [Available from:]
  23. NHS. Vitamin B6. Date Accessed: 24/05/19. [Available from:]
  24. DeGroot LJ, et al. Role of pyridoxal phosphate in thyroid hormone biosynthesis. Endocrinology. 1968; 83(6):1253-8.
  25. Plus M. NIH. Folic acid in the diet. Date Accessed: 24/05/19. [Available from:]
  26. Chidambaram B. Folate in pregnancy. J Pediatr Neurosci. 2012; 7(2):81-.
  27. NHS. Vitamin B12 or folate deficiency anaemia. Date Accessed: 30/05/19. [Available from:]
  28. NIH. Vitamin B12. Date Accessed: 30/05/19. [Available from:]
  29. NIH. Pantothenic Acid. Date Accessed: 30/05/19. [Available from:]
  30. Bean WB, et al. Pantothenic acid deficiency induced in human subjects. J Clin Invest. 1955; 34(7, Part 1):1073-84.
  31. NIH. Biotin. Date Accessed: 30/05/19. [Available from:]
  32. Rowland I, et al. Gut microbiota functions: metabolism of nutrients and other food components. Eur J Nutr. 2018; 57(1):1-24.
  33. Sanders LM, et al. Choline: Dietary Requirements and Role in Brain Development. Nutr Today. 2007; 42(4):181-6.
  34. Institute LP. Oregon State University. Choline. Date Accessed: 30/05/19. [Available from:]
  35. Kowey P. The Role of Potassium. Lobo R.A. CPG, Paoletti R., Bruschi F, (eds). Springer: Boston, MA; 2002.
  36. NHS. Potassium Test. Date Accessed: 31/05/19. [Available from:]
  37. Institute LP. Oregon State University. Sodium (Chloride). Date Accessed: 31/05/19. [Available from:]
  38. Meeroff JC, et al. Electrolytes of the gastric juice in health and gastroduodenal diseases. The American journal of digestive diseases. 1973; 18(10):865-72.
  39. NHS. Others: Sodium chloride (salt). Date Accessed: 31/05/19. [Available from:]
  40. NHS. Calcium. Date Accessed: 31/05/19. [Available from:]
  41. Beto JA. The role of calcium in human aging. Clin Nutr Res. 2015; 4(1):1-8.
  42. Demontiero O, et al. Aging and bone loss: new insights for the clinician. Ther Adv Musculoskelet Dis. 2012; 4(2):61-76.
  43. Institute of Medicine (US) Committee to Review Dietary Reference Intakes for Vitamin D and Calcium. Dietary Reference Intakes for Calcium and Vitamin D. National Academies Press: Washington (DC); 2011.
  44. Lonnerdal B. Calcium and iron absorption--mechanisms and public health relevance. International journal for vitamin and nutrition research Internationale Zeitschrift fur Vitamin- und Ernahrungsforschung Journal international de vitaminologie et de nutrition. 2010; 80(4-5):293-9.
  45. Institute LP. Phosphorus Date Accessed: 31/05/19. [Available from:]
  46. Plus M. NIH. Phosphorus in the diet. Date Accessed: 31/05/19. [Available from:]
  47. Takeda E, et al. The regulation and function of phosphate in the human body. BioFactors (Oxford, England). 2004; 21(1-4):345-55.
  48. Carvil P, et al. Magnesium and Implications on Muscle Function. 2010. 48-54 p.
  49. NIH. Magnesium. Date Accessed: 31/05/19. [Available from:]
  50. NHS. Iron Date Accessed: 31/05/19. [Available from:]
  51. Lopez A, et al. Iron deficiency anaemia. The Lancet. 2016; 387(10021):907-16.
  52. NIH. Iron. Date Accessed: 31/05/19 [Available from:]
  53. Institute LP. Oregon State University. Zinc. Date Accessed: 31/05/19. [Available from:]
  54. Prasad AS. Discovery of human zinc deficiency: its impact on human health and disease. Adv Nutr. 2013; 4(2):176-90.
  55. Willis MS, et al. Zinc-induced copper deficiency: a report of three cases initially recognized on bone marrow examination. American journal of clinical pathology. 2005; 123(1):125-31.
  56. Bost M, et al. Dietary copper and human health: Current evidence and unresolved issues. Journal of Trace Elements in Medicine and Biology. 2016; 35:107-15.
  57. NHS. Others: Copper. Date Accessed: 07/06/19. [Available from:]
  58. Institute LP. Oregon State University. Copper. Date Accessed: 06/07/19. [Available from:]
  59. NHS. Others: Manganese. Date Accessed: 07/06/19. [Available from:]
  60. Institute LP. Manganese. Date Accessed: 07/06/19. [Available from:]
  61. Tuschl K, et al. Manganese and the brain. International review of neurobiology. 2013; 110:277-312.
  62. NIH. Selenium. Date Accessed: 07/06/19. [Available from:]
  63. NHS. Others: Selenium. Date Accessed: 07/06/19. [Available from:]
  64. Anderson RA. Nutritional role of chromium. The Science of the tTotal eEnvironment. 1981; 17(1):13-29.
  65. Cefalu WT, et al. Role of Chromium in Human Health and in Diabetes. Diabetes Care. 2004; 27(11):2741-51.
  66. NHS. Others: Chromium. Date Accessed: 07/06/19. [Available from:]
  67. Sardesai VM. Molybdenum: an essential trace element. Nutrition in clinical practice : official publication of the American Society for Parenteral and Enteral Nutrition. 1993; 8(6):277-81.
  68. NHS. Molybdenum. Date Accessed: 07/06/19. [Available from:]
  69. NHS. Iodine. Date Accessed: 07/06/19. [Available from:]
  70. Chung HR. Iodine and thyroid function. Ann Pediatr Endocrinol Metab. 2014; 19(1):8-12.

Please log in to your store account

To share with your friends, log in is required so that we can verify your identity and reward you for successful referrals.

Log in to your account If you don't have a store account, you can create on here

Check out why Hueligans love us on @huel

Use #huel in your Huel photos for the chance to feature on our Instagram

Join our VIP list

Never miss out on new products, exclusive offers, and more when you join the Huel mailing list.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. You can unsubscribe at any time. Huel Privacy Policy