Do supplements work? | BBC Good Food

Do I need to take vitamins and minerals?

First off, no supplement is a substitute for a balanced, varied diet. However, there are specific nutrients that may be beneficial in supplement form for certain groups of people. These include:

• Vitamin D – all babies under one year of age should receive a supplement providing 8.5-10mcg of vitamin D (unless they are receiving more than 500ml of formula milk). Adults and children over one year should supplement 10mcg of vitamin D during the autumn and winter months.
• Folic acid – women who are pregnant, planning a pregnancy or who may become pregnant should supplement with 400mcg folic acid from preconception until 12 weeks of pregnancy.
• Iodine – given that the main food sources in the UK diet are dairy and fish, supplementing up to 150mcg daily may also be useful for vegans.
• Other – people who have certain health conditions, such as iron-deficiency anaemia, Crohn’s or coeliac disease may benefit from supplementation. Refer to your GP for guidance.

Do multi-vitamins work?

There is some evidence to suggest that users of multivitamins may be at lower risk of developing certain conditions, like heart disease. The UK National Diet and Nutrition Survey is of the view that many ‘high street’ multivitamins (which typically contain nutrients to the UK reference intake (RI) and are generally considered safe) may be beneficial for those at risk of poor nutritional intake. So, although supplements are never a substitute for a poor diet, there is evidence that they may help reduce nutritional gaps in certain groups.

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However, there is inconsistent evidence for single or combination nutrients at higher doses, making it hard to provide a solid answer to the question of whether supplementing with specific vitamins or minerals is effective. For example, calcium with vitamin D is sometimes prescribed for the prevention of fracture in the elderly, but the jury is still out on whether this is effective. Certain carotenoids (such as vitamins C and E), though, do have proven benefits for slowing the progression of eye conditions such as cataracts and age-related macular degeneration. Similarly, prenatal supplements appear to help mums-to-be get enough nutrients, including folic acid and iron.

The problem with studies tends to be that they use different products and doses, and that formulations are subject to frequent change. What’s more, the people most interested in supplements and most likely to take them tend to follow a healthier diet and lifestyle anyway.

In general, nutritionists would agree that a multivitamin is not a ticket to optimal health and, when it comes to dosage, more is not always best.

Which other supplements should I take?

As well as the vitamins and minerals listed above, there are a host of other products that may be useful in specific circumstances.

• Pro- and prebiotics – the research assessing the role of the gut microbiome and the use of ‘good bacteria’ is gaining pace, with evidence accumulating that these products may alleviate gut issues and potentially improve overall health.
• Co-enzyme Q10 – the third most consumed supplement, perhaps because low levels of this nutrient have been associated with numerous conditions including fibromyalgia, diabetes and heart disease. However, this supplement may not be suitable if you have been diagnosed with diabetes or are on prescribed blood thinning medication.
• Fish oil supplements – research suggests that people who eat oily fish at least twice a week have a lower risk of dying from heart disease, but the evidence from taking fish oil supplements appears less convincing.
• Herbal supplements – a popular alternative for general well-being, mood and memory, their use is often driven by the misconception that being from a ‘natural’ source makes them a risk-free option. This may not be the case and, although some people may gain benefits from their use, others may not.

Which is the best format for supplements?

You no longer just pop a pill to take supplements – sprays, gummies, injections and transdermal patches are now often available. Many of these methods are designed to bypass the digestive process because digestion may slow absorption and reduce nutrient availability. There are also other reasons for different formats, whether that’s powders for fitness fans or gummies for children.

Each format has its pros and cons – for example while gummies may be a tastier option, they are also more susceptible to heat and moisture which can affect their stability and shelf life. Gummies also tend to contain added sugars and calories and have a limited nutrient profile due to formulation restraints.

Sometimes the effectiveness of the format depends on the nutrient involved. For instance, transdermal patches appear to be effective for the supply of magnesium but less so for iron, which would be better delivered in pill format. Similarly, nutrients like vitamin D may be more effectively delivered as a liquid emulsion or ‘drops’, this simulates the digestive process, making the nutrient easier to absorb.

Another big question for consumers is whether to opt for synthetic or natural versions of nutrients. For example, there is some evidence that synthetic folic acid is more harmful than the natural form (folate) found in foods. Similarly, natural forms of nutrients such as vitamin E (d-alpha-tocopherol) may be twice as easy for us to absorb as its synthetic (dl-alpha-tocopherol) counterpart.

Is there a risk I could take too much of a vitamin or mineral?

Concern about overdosing is nothing new, especially with the increase in both popularity and variety of supplements.

Generally speaking, when water-soluble nutrients like vitamins C and the B group are taken in excess, they are flushed out of the body by the kidneys via your urine. The one exception to this is vitamin B12: the body stores about 1-5mg in the liver.

It’s a different story, however, for fat-soluble vitamins – such as vitamin A, vitamin D, vitamin E and vitamin K. These are stored in the body and may accumulate to unwanted levels. Minerals are also stored (for example calcium and magnesium are stored in the bones), with the main difference being that minerals are mainly stored to provide structure and to support your metabolism.

So, should I take supplements?

People turn to supplements for a number of reasons, whether as an ‘insurance policy’, to make up for dietary indiscretions or to improve their health, appearance or fitness levels. If you choose to take supplements, do your homework: understand why you are taking the product, what you are hoping to achieve and gather the information you need to make an informed choice about the product.

If you’re on prescribed medication or have a certain medical condition, check with your GP before taking supplements. This is because some supplements or nutrients may interact with medication, be unsafe if you have been diagnosed with a certain health condition or if you are due to undergo surgery.

Further reading…

Vitamins: what do I need?
Vital minerals: what do I need?
Vitamin health hacks

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