Dave Shaw: 6 things you need to know about supplements

Do you really need to take supplements?Photo / Thinkstock

In an ideal world, a balanced diet provides all the nutrients we need. But our crazy obsession with healthy eating has led us to believe supplements are vital for our health.

For some people this is true, but not for the majority of us.

Here are six things you need to know about supplements before you start popping pills and making protein shakes.

1. Supplements don't replace food

Food contains a complex combination of nutrients working together to support our health. In a balanced diet, each food complements another to provide our bodies with the right combination of good stuff. Although supplements contain many of the same nutrients as food, don't make the mistake of thinking you don't need to eat your recommended daily intake of fruit and veg because you had a multivitamin in the morning. It's more effective to get goodness from wholesome fruit and veg, lean meats, fish and low fat dairy.

2. You can overdo it

Nutrients are good for us, so the more the better, right? Wrong. Our bodies can only tolerate certain levels of some nutrients and excessive doses can lead to toxicity. Keep this in mind if you're swigging a 'supplement cocktail' every morning. For instance, fat-soluble vitamin A can accumulate to toxic levels in your body if taken in doses that significantly exceed the recommended daily intake. In the short term, this can cause headaches and dry skin. Looking ahead, it can lead to joint pain and poor bone health.

3. There can be side effects

Supplements can lead to a variety of side effects - anything from stomach cramps to weight gain. They can also react with other medications. It is well known that increasing levels of vitamin K in your diet can counteract the treatment of blood thinners such as warfarin. It's really important to let your doctor know about any dietary supplements you're taking before you start any medical treatment.

4. Not all supplements are regulated

Different countries have different food and drug regulation standards - some have none. This means what goes into their pills, powders, capsules, bars and shakes is not as closely regulated as it should be. If these products become contaminated, they can do damage to your health and even place you at risk of doping if you're a competitive athlete. So, if you do buy supplements, make sure they come from a reliable source.

5. Don't be sucked in by big claims

Many supplement manufacturers market their products by making sketchy health claims based on dubious evidence. This doesn't mean what they're saying isn't true. However, you're probably buying a product that won't be of any benefit if you're already eating a good diet. An example of this is the promotion of glucosamine to improve joint health when the evidence for its true effect is inconclusive. Consider this, if what manufacturers say is true - then why aren't these supplements being used by every person in every house, hospital and rest home around he world? It's because more often than not, they don't work.

6. Who should take supplements then?

If you're not sure if you need supplements to boost your diet, talk to your doctor or a dietitian. Here are a few situations when you should consider taking a supplement:

• Your doctor has said you have a deficiency.
• You're pregnant or trying to be.
• You're having trouble putting on, or maintaining, your weight.
• You're following a restrictive diet or cutting out food groups.
• You're at risk of osteoporosis
• You're following a vegan diet.
• You have heavy bleeding during menstrual periods.
• You regularly donate blood.
• You have a medical condition that affects your absorption of nutrients.
• You struggle to meet nutrient requirements through diet alone

* Dave Shaw is a registered dietitian and nutritionist. Follow him on Twitter here.