The RDA (Recommended Daily Allowance) is the amount of a specific nutrient that we need to maintain good health. Similar nutritional reference values also exist such as the RNI (Recommended Nutritional Intake) and EAN (Estimated Average Requirements), which fulfills a similar role. However, with everyone being so different from a genetic and environmental stand point, how do the RDA’s apply to you, and can they be accurate for everyone? This article will explore the purpose of the RDA’s, and how they can relate to your health.

 

Origin of the RDA

The RDA values were created during the second world war, with the purpose of calculating the nutritional requirements for the military’s rations to prevent the development of diet related diseases among soldiers. It was then further developed to apply to the rest of the public, but with the same aim – preventing diseases which arise from deficiencies. The RDA values are now reviewed every 5 years, and are now set based on the minimum amount required to prevent the development of deficiency. E.g the average amount of vitamin C a person needs a day to prevent scurvy. The modern RDA’s are not based on the optimal amount required by the body of any specific nutrient, but are a value which is deemed obtainable by the average modern person, through modern diet to prevent disease.

 

For the average person, consuming the RDA of all nutrients will prevent dietary deficiency related disease, but, this doesn’t mean you are necessarily healthy. If we look at vitamin C, your dietary requirements can vary by as much as ten fold due to genetic variance alone. In addition to this there are additional environmental factors which can cause an increased demand on the body. Common examples of these are:

Smoking – Smoking is a source of a number of toxic chemicals and radicals which will damage the body. In order to protect the body and prevent damage, your bodies nutritional requirements are massively increased, especially for nutrients which defend against radicals such as vitamin C and vitamin E.

Diet – A poor diet not only doesn’t provide you with your RDAs of nutrients, but may also increase the demand for nutrients. Heating foods up to high temperatures (especially frying them) causes radicals to develop in the food, which will damage your body. Many highly processed foods suppress the immune system, and so again increase the demand of nutrients to maintain a healthy body. Foods which contain pesticides or cleaning chemicals

Exercise – Although exercise is needed to ensure a healthy body, it increase the amount of radicals that our body produces (such as hydrogen peroxide), which, if our body cannot protect against, will damage our cells. Exercising means that our body has a greatly increased nutritional requirement to ensure that we are able to continue to exercise and stay healthy – the RDA is just not enough for this.

Age – As we age, particularly between 40 and 50, our body starts to lose the ability to utilize certain nutrients efficiently. For example,  our body can convert beta-carotene to active vitamin A in a 2:1 ratio, so for 10mg beta-carotene your body will make 5mg of active vitamin A. As we age, our body will be less efficient and so less active vitamin A will be created, which will have a negative effect on your health. In order to maintain good health as you age you will need to increase the amounts on nutrients consumed, to compensate  for the loss in efficiency.

Pollution – This is a factor which is difficult to control. Pollutants can include heavy metals, radicals and toxins, all of which will damage your cells. In order to maintain your cells health, you will require much more nutrients than the RDA currently recommends. This is of particular importance for people living in cities or heavily built up area, because pollution levels are highest there.

In extreme circumstances you body may require over 100 times the RDA of nutrients to maintain healthy function.

 

The RDA is little more than the minimum nutritional requirements for the average population to avoid developing nutritional deficiencies. There are a number of environmental and genetic factors which impact on the amount of each nutrient the body requires, and it is likely that you will need much more than the RDA in order to maintain a truly healthy lifestyle.