23 April 2007

To supplement, or not to supplement

Just because you're eating healthily, doesn't mean you're getting all the nutrients your body needs. You might actually have to include a good multivitamin in your shopping list.

The topic of vitamin and mineral supplementation is both confusing and controversial. A lot has been said about the topic, but still the debate is far from over.

While no-one doubts the crucial part that these nutrients play in human health and survival, experts are debating whether it is really necessary to pop tablets to ensure an adequate intake of nutrients, or whether a healthy diet is enough to satisfy our daily vitamin and mineral needs.

Brent Murphy, a South African pharmacist and executive council member of the Health Products Association, shared his perspectives at a recent CytoTech press conference – and certainly made a few valid points.

Two types of supplementation
According to Murphy, there are two types of supplementation:

  • 100% RDA doses: These are defined by the World Health Organisation as the very minimum required (not the maximum or ideal) to prevent deficiency diseases. This can easily be obtained from a healthy diet.
  • Optimal health and disease-prevention doses: These are scientifically determined doses, higher than RDA, based on risk-benefit scientific models, incorporating scientific research. These doses cannot be obtained from the diet and must be supplemented.

Murphy uses vitamin C as an example. If you take the recommended 45-60mg of vitamin C, i.e. 100% of the Recommended Daily Allowance (RDA), you won't get scurvy (a disease directly related to vitamin C intake).

But this amount isn't enough for you to benefit from the antioxidant properties of the vitamin. In order to protect your immune cells, reduce cholesterol etc., you need at least 500-1000mg of vitamin C every day.

In order to get this, you'll have to eat 20 oranges a day – an impossible feat. As you simply cannot get 500-1000mg by means of what you consume, you will need to take a vitamin C supplement.

"RDA is the bare minimum you need. You can get this from the food you eat," Murphy says. "But optimal doses are impossible to get from your diet."

Today vs. yesterday
When asked what people did before supplements were available, he points to the fact that the life expectancy of people was generally much shorter. This could have been because, back then, people didn't take optimal doses of vitamins and minerals.

He also says that our modern lifestyle – which is characterised by stress, too little exercise, unhealthy diets etc. – calls for a higher vitamin and mineral intake.

Another factor could be that the food we're eating simply isn't of the same quality than it was a few decades ago. He mentions, for example, studies that have shown that oranges don't contain as much vitamin C as they did a few years ago.

These factors all contribute to the fact that people aren't getting what their bodies are asking for: optimal amounts of vitamins and minerals.

General rules
There are a few general rules for vitamin and mineral intake, according to Murphy:

  • Mega-dosing on vitamins is generally safe. However, doses of vitamin A should not exceed 10 000IU per day (as this vitamin can be toxic to the liver) and 5000IU if you're pregnant. Long-term doses of vitamin B3 (niacin) should not exceed 1000mg per day or liver damage could occur. Long-term doses of vitamin B6 (pyridoxine) should not exceed 100mg per day or nerve damage could occur.
  • Mega-dosing of minerals (e.g. selenium, chromium, magnesium, calcium, boron etc.) is not safe. Therefore, minerals should always be taken in RDA amounts.
  • Children older than 12 can take adult doses of vitamins and minerals, children between the ages of seven and 12 should take half the adult dose, and children between four and seven should take a quarter of the adult dose.
  • Vitamins and minerals are safe to take during pregnancy. However, herbs haven't been proven to be safe, and should be avoided (check the labels of multivitamins to see if herbs have been included).

"You can take very high doses of vitamins (except for vitamin A, B3 and B6) without safety concerns," Murphy says. "But it's a very different story with minerals. These can be toxic."

Interestingly, he notes that yellow urine is not a sign of wasted vitamins. There is only one vitamin that causes yellow urine, and that is riboflavin (vitamin B2). The rest of the vitamins are colourless. And whether riboflavin is fully metabolised or not, it still causes urine to look yellow.

What you need to take
Murphy suggests the following basic supplements for people who want to ensure optimal health, even if they're following a healthy diet:

  • A good, high-strength multivitamin, which contains antioxidants, vitamins and minerals.
  • A calcium and magnesium supplement.
  • Omega-3 fats, if you're not eating fish four times a week.
  • If you drink too much alcohol, or follow a high-fat diet, he suggests you take silymarin (milk thistle) for liver protection.

A calcium and magnesium supplement is suggested on top of a multivitamin, because "it is impossible to put enough calcium and magnesium in a single-dose multivitamin", Murphy says.

- (Carine van Rooyen, Health24)

Read more:
Are vitamin supplements fatal?
Vitamin pills: do we need them?


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