​Guide to Vitamins & supplements
We spend millions on vitamin and mineral supplements per year. Recently there have been several reports in the scientific literature casting doubt about the benefits of taking daily supplements. There are various types of supplements some prescribed by the doctor such as iron for those with iron deficiency, vitamin drops given to infants, vitamin D and calcium given to the elderly, folic acid given during pregnancy. But do we really need to be taking vitamin and mineral supplements if we are healthy and following a well balanced diet?
Most nutrition experts believe that they are not necessary and they should not be substituting a ‘healthy diet’. They question whether taking a nutrient in supplement form acts the same as nutrients provided by food that has other ‘active ingredients’ such as phytochemicals which are know to have protective health benefits. Also food provides a balance of many nutrients together with fibre and this is what we should be recommending.
What is the evidence?
There are situations where an individual may not be able to obtain adequate vitamins and minerals from the diet such as when appetite is poor, during illness and recovery, or when the gut does not function and nutrients are not adequately absorbed. There is evidence that those who smoke require extra vitamin C. Those who drink heavily need extra B vitamins. There is also some convincing evidence to take a high dose of vitamin C with zinc to help reduce the duration and severity of a cold. The elderly can benefit from multivitamins as their intake, absorption and dietary intake may be poor. Trials on using vitamin C, E and beta-carotene in heart disease and cancer patients have shown both positive and negative effects. Selenium in a mineral that tends to be difficult to obtain from our diets and some experts recommend this antioxidant. Folic acid is advised to all women planning to get pregnant and during pregnancy to protect against birth defects.
Can high doses be toxic?
Vitamin A is a fat soluble vitamin that can be dangerous if taken in large doses as it is stored in the liver and hard for the body to get rid of. This is why pregnant women are advised against eating liver while pregnant. High intakes of iron, selenium and zinc are toxic and vitamin C taken in excessive amount will cause a stomach upset. Calcium supplements are not advised if you have kidney stones, or cancer. Fish oils coming from polluted seas have high levels of toxins and some brands have previously recalled their products from the supermarket shelves.
Consumers also need to be made aware that taken single dose supplements can cause nutritional imbalances. The beauty of eating a well balanced diet is that the nutrients work together and within the body. When we start to take single doses we can upset the balance. Therefore, high dose single supplementation is not recommended.
Top Tips
Most nutrition experts believe that they are not necessary and they should not be substituting a ‘healthy diet’. They question whether taking a nutrient in supplement form acts the same as nutrients provided by food that has other ‘active ingredients’ such as phytochemicals which are know to have protective health benefits. Also food provides a balance of many nutrients together with fibre and this is what we should be recommending.
What is the evidence?
There are situations where an individual may not be able to obtain adequate vitamins and minerals from the diet such as when appetite is poor, during illness and recovery, or when the gut does not function and nutrients are not adequately absorbed. There is evidence that those who smoke require extra vitamin C. Those who drink heavily need extra B vitamins. There is also some convincing evidence to take a high dose of vitamin C with zinc to help reduce the duration and severity of a cold. The elderly can benefit from multivitamins as their intake, absorption and dietary intake may be poor. Trials on using vitamin C, E and beta-carotene in heart disease and cancer patients have shown both positive and negative effects. Selenium in a mineral that tends to be difficult to obtain from our diets and some experts recommend this antioxidant. Folic acid is advised to all women planning to get pregnant and during pregnancy to protect against birth defects.
Can high doses be toxic?
Vitamin A is a fat soluble vitamin that can be dangerous if taken in large doses as it is stored in the liver and hard for the body to get rid of. This is why pregnant women are advised against eating liver while pregnant. High intakes of iron, selenium and zinc are toxic and vitamin C taken in excessive amount will cause a stomach upset. Calcium supplements are not advised if you have kidney stones, or cancer. Fish oils coming from polluted seas have high levels of toxins and some brands have previously recalled their products from the supermarket shelves.
Consumers also need to be made aware that taken single dose supplements can cause nutritional imbalances. The beauty of eating a well balanced diet is that the nutrients work together and within the body. When we start to take single doses we can upset the balance. Therefore, high dose single supplementation is not recommended.
Top Tips
- Try to get all your nutrients from a well balanced diet where possible.
- Supplementation should not substitute a ‘healthy diet’.
- Take folic acid 400 micrograms – preconception and during pregnancy (prevents birth defects) ask your doctor or pharmacist for advice.
- Omega 3 supplements – (check fish oils are free from dioxins and mercury) or go for flaxseed capsules if you are unable to obtain from dietary sources.
- B6 supplements can be used to treat premenstrual syndrome, but don’t go above 10mg per day, as high doses can cause neurological symptoms.
- Iron supplements can be prescribed for iron deficiency anaemia, commonly seen in women with high menstrual loses, or in the young or elderly who have poor intakes, or poor gut absorption. The GP will take bloods.
- Calcium can be prescribed by the doctor for those with family history of osteoporosis.
- Children’s vitamins drops – ask your doctor or pharmacist.
- A general multi-vitamin can be used in those on weight loss programmes, if you have been unwell, or as an insurance policy
ALWAYS CONSULT YOUR DOCTOR, PHARMACIST OR DIETITIAN FOR ADVICE BEFORE COMMENCING A SUPPLEMENT REGIME