• Question: How are vitamins identified in food ie use of tests? And how would a diet without vitamins impact the body?

    Asked by indigoblue on 30 Apr 2020.
    • Photo: Mery Shahin

      Mery Shahin answered on 30 Apr 2020:


      That is a very interesting question! Chromatography is a common way of identifying vitamins in food. Chromatography works by separating the different substances found in food based on their unique interaction properties. Each substance then gives out a signal (we call this a peak). We can compare this peak to existing references for known substances to identify which substance corresponds to the peak we are interested in. So vitamin A will produce a different peak to vitamin B and to vitamin C and so on.

      The lack of vitamins in a diet is called hypovitaminosis (hypo means under/below normal). Each vitamin has a different function in the body so its absence will impact your health differently. For example, the absence of vitamin C causes scurvy which is characterised by weakness, gum and skin problems and anemia and the lack of vitamin A can cause night blindness.

    • Photo: Kim Liu

      Kim Liu answered on 30 Apr 2020: last edited 30 Apr 2020 11:33 am


      Typically, you can identify chemical compounds in a sample by mashing it up and applying a technique called chromatography which separates chemicals by how much they stick to a tube the mixture is flowing through. You may have seen demonstrations where inks can be separated into different colours by using water to push it through paper – this is the same principle. After that, the separated compounds are then identified using mass spectrometry – this is a clever technique which effectively weighs the molecules being separated. Most chemical compounds have different molecular weights, and these mostly give unique signals in mass spectrometry.

      Vitamins are chemicals which assist the enzymes of your body in their function, and are usually not easily produced by the body. If you don’t eat enough vitamins, important enzymes stop working. A famous example is lack of vitamin C which prevents connective tissue (collagen) from being produced. This leads to, amongst other problems, weakened gums and teeth – symptoms of scurvy.

    • Photo: Maria Marti

      Maria Marti answered on 30 Apr 2020:


      You already had very nice answers to your question. To add a bit more information about vitamin C in particular, the way its connection with scurvy was discovered is very interesting and an example of one of the first clinical trials. For a centuries, sailors commonly suffered from scurvy and had tried different remedies to treat it (including eating the ship’s rats!). In 1747, Dr James Lind, a surgeon in the Royal Navy, started treating small groups of sailors with some of these remedies: including vinegar, cider, sea water or lemons and oranges. He found out that citrus fruits, which we now know are very rich in vitamin C, were the most efficient treatment. However, the word vitamin, meaning a molecule that our body needs to function but can not produce by itself, would not be invented until the year 1912. This brings us back to the sailors who would get vitamin C from eating rats, as they, unlike humans, can produce the vitamin C molecule.

    • Photo: Wei Xun

      Wei Xun answered on 30 Apr 2020:


      Great answers already. Also to add, in the UK unless a person is on a severely restrictive diet, the chances that anyone would be deficient in most vitamins (which the body gets mostly from the food that we eat) are low.

      One exception is vitamin D, which we need to make from being exposed to sunlight for strong bones and muscles. In this country, the sunshine is only strong enough in the spring and summer months for this to happen, especially for people with darker skin tones. So some groups are recommended to take Vit D supplements to keep them healthy:
      see https://www.nhs.uk/live-well/healthy-body/how-to-get-vitamin-d-from-sunlight/

    • Photo: Nina Rzechorzek

      Nina Rzechorzek answered on 30 Apr 2020: last edited 30 Apr 2020 9:00 pm


      Hi indigoblue – great question and lots of good answers already. Just to add that a deficiency in either thiamine (vitamin B1) or cobalamin (vitamin B12) can cause neurological (brain problems). Having too much a of vitamin can cause problems too:
      Vitamin D toxicity, also called hypervitaminosis D, is a rare but potentially serious condition that occurs when you have excessive amounts of vitamin D in your body. Vitamin D toxicity is usually caused by large doses of vitamin D supplements — not by diet or sun exposure. That’s because your body regulates the amount of vitamin D produced by sun exposure, and even fortified foods don’t contain large amounts of vitamin D. The main consequence of vitamin D toxicity is a buildup of calcium in your blood (hypercalcemia), which can cause nausea and vomiting, weakness, and frequent urination. Vitamin D toxicity might progress to bone pain and kidney problems, such as the formation of calcium stones.
      Hypervitaminosis A refers to the toxic effects of ingesting too much preformed vitamin A. Symptoms arise as a result of altered bone metabolism and altered metabolism of other fat-soluble vitamins.

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