In 1912, Dr Casimir Funk1 reported on a series of substances in food he called ‘vitamines’ which he noted were effective against certain deficiency diseases such as beri-beri and scurvy. The term ‘vital amine’ was coined because it was believed all the compounds contained an amine (nitrogen) group – though we now know this is not always the case. Despite his theories being somewhat limited, Funk is hitherto regarded as the founder of vitamins.
Vitamins are organic (carbon-based) compounds, especially abundant in fruits, vegetables and grains and also meat, fish, eggs and dairy products. Only needed in very small amounts, i.e. milli- or micrograms and therefore classed as micronutrients, they are essential to maintain health and regulate hundreds of metabolic reactions occurring within the body. There are 13 essential vitamins which are classified as being either water or fat soluble. This characteristic influences how they are transported and stored in the body, their mode of action and whether or not excess intake can be toxic. The latter is especially salient for the fat soluble vitamins when consumed in excessive quantities. Conversely, whilst water soluble vitamins are generally not stored in the body and therefore less likely to have toxic effects, their bioavailability can be affected in a number of ways, e.g. by a person’s age, other components of the diet and medications.
A varied diet of naturally occurring foods should contain a plentiful supply of vitamins without the need to take vitamin supplements. There are some exceptions, one being vitamin D which is mainly formed through the action of sunlight on the skin. In July 2016 Public Health England published advice on vitamin D supplementation which is available here
Table 1: Fat soluble vitamins – A, D, E and K
Vitamin | Promotes | Sourced from |
---|---|---|
A |
|
|
D |
|
|
E |
|
|
K |
|
|
2
Table 2: Water soluble vitamins – B complex and C – excepting Vitamin B12 these are not normally stored in the body.
All B vitamins act as coenzymes, i.e. they help enzymes catalyse chemical reactions in the body.
Water soluble vitamins are sensitive to heat so care should be taken with preparation.
Vitamin | Promotes/Functions | Sourced from |
---|---|---|
Thiamin (B1) |
|
|
Riboflavin (B2) |
|
|
Niacin (B3) |
|
|
Pantothenic Acid (B5) |
|
|
B6 |
|
|
Biotin (B7) |
|
|
Folate (B9) |
|
|
B12 (Cobolamin) |
|
|
Vitamin C (Ascorbic Acid) |
|
|
2
Additional information on vitamins, including recommended intakes and the effects of deficiency and toxicity, can be found on the NHS web pages here
References
1. Funk C. The etiology of the deficiency diseases. Beriberi, polyneuritis in birds, epidemic dropsy, scurvy, experimental scurvy in animals, infantile scurvy, ship beriberi, pellagra. Journal of State Medicine. 1912;20:341.
2. McGuire, M. and Beerman, K.A. (2013). Nutritional Sciences From Fundamentals to Food. 3rd ed. US: Cengage Learning, pp. 420-421, 462