Q and A

Vitamins and minerals

This factsheet will aim to give you a background into vitamins and minerals. It will explain why they are important for keeping your body healthy and show you some common foods that contain different vitamins and minerals.

What are vitamins?

Vitamins are chemical compounds that your body needs in small amounts. They help to keep all of your cells and tissues working properly.  Your body cannot make the vitamins it needs so you must get them through diet.

Some specific roles of vitamins include:

  • Helping your body’s metabolism (making energy from food)
  • Controlling the growth of your cells
  • Helping enzymes to work properly in your cells

There are two types of vitamins

1) Fat-soluble

Fat-soluble vitamins (A,D,E and K) dissolve into fat before they can be absorbed and used by the body. As the body can store these vitamins, its means it is not as important to consume them through diet every day.

2) Water-soluble

Water-soluble vitamins (C and all the B vitamins) dissolve into water before being absorbed by the body. Any water-soluble vitamin that is not used by the body will be passed out through the urine and will not be stored. This means you need to consume enough of these vitamins through diet on a daily basis.

What happens when your body doesn’t get enough vitamins?

As vitamins are important for keeping your body healthy, not getting enough can cause problems. However, this only happens when you have very low levels of vitamins in your body – known as a deficiency.

Having a varied diet is the best way to avoid deficiency and get all of the vitamins that you need. Sometimes supplements are used to bring vitamin levels up to normal if you have a deficiency.

How much do I need?

Your body only needs very small amounts. However, some foods contain a lot more than others. This makes eating more of these foods an easier way to give your body all of the vitamins that it needs (see table 1 and 2).

For food that comes in packaging, the label usually tells you how much of certain vitamins there are in the food. Food packaging usually shows the RDA values for the vitamins in the food too. RDA stands for recommended daily allowance. This is the daily amount of a vitamin or mineral needed to keep most people healthy.

RDA values are there to help you track how much nutrients you are getting from your diet – but they can appear confusing. Always trying to eat a balanced diet full of fruits and vegetables is the easiest way to give your body all of the vitamins and minerals it needs.

Table 1: Sources of vitamins and their RDAs*

Vitamin Source RDA
A Leafy vegetables 800 mg
B1 Vegetables 1.1 mg
B2 Dairy products 1.4 mg
B3 (Niacin) Meat, vegetables 16 mg
B5 (Pantothenic acid) Meat, broccoli 6 mg
B6 Meat, vegetables 1.4 mg
B7 (Biotin) Liver, vegetables 50 mg
B9 (Folic acid) Leafy vegetables, cereals 200 mg
B12 Meat/animal products 2.5 mg
C Fruits, vegetables 80 mg
D Fish, eggs 5 mg
E Fruits, vegetables 12 mg
K Leafy green vegetables 75 mg

* RDA: Recommended Daily Allowance (mg or mg). Based on European (EU) recommendations

What are minerals?

Dietary minerals are chemical elements other than carbon, hydrogen, nitrogen and oxygen. Your body only needs them in small amounts, but they are still important to keep you healthy. Your body cannot make the minerals it needs so you must get them through diet.

Their specific roles vary, but like vitamins, many are used to help with metabolism. Also, like vitamins, it is possible to be deficient in a mineral if you don’t get enough from your diet.

Table 2: Sources of dietary minerals and their RDAs*

Dietary Mineral Source RDA
Potassium Legumes, whole grains 2000 mg
Chloride Table salt 800 mg
Chromium Whole grains, lean meat, cheeses 40 mg
Calcium Dairy products, green leafy vegetables 800 mg
Phosphorus Meat, fish, rice, oats 700 mg
Magnesium Nuts, tomatoes, beans 375 mg
Zinc Eggs, red meat, yoghurt 10 mg
Iron Grains, eggs, beans, tofu 14 mg
Manganese Brown rice, beans, berries 2 mg
Copper Mushrooms, greens, seeds 1 mg
Iodine Eggs, yoghurt, fish 150 mg
Selenium Cheese, garlic, seeds, tuna, turkey 55 mg
Molybdenum Tomatoes, onions, carrots 50 mg
Fluoride Tap water 3.5 mg

* RDA: Recommended Daily Allowance (mg or mg). Based on European (EU) recommendations

Do we all need the same amounts of vitamins and minerals?

The RDA values of vitamins and minerals apply to most people’s dietary needs. However, some people will need more or less of certain vitamins and minerals during different stages of life. These include pregnant or breastfeeding women, children, and the elderly. Your GP or health worker will be able to best advise you on your own nutritional needs.

Lifestyle can also influence how your body absorbs and uses vitamins and minerals. For instance, smoking can reduce calcium absorption. [1] This then reduces bone strength and increases the risk of fracture.

Do I need to take vitamin or mineral supplements?

The only disease a vitamin/mineral will cure is the one caused by a deficiency of that vitamin/mineral. This means that there is little benefit from taking in larger amounts (usually by supplements).  There is also a small risk of developing vitamin toxicity. This can happen after eating too much of a certain food or taking high dose vitamin or mineral supplements.

However, if you are struggling to eat a balanced diet and provide your body with enough nutrients from food, you should consider speaking with your GP, health worker or dietician about this.

Vitamins and minerals in people living with HIV

Eating a balanced diet with enough vitamins and minerals will help keep your body healthy. This is true for HIV positive and negative people. Some studies have shown HIV positive people are more likely to be deficient in certain vitamins and minerals. This was linked to poorer health and risk of developing HIV-related diseases. However, these findings only applied to people who were not taking antiretrovirals (ARVs).

When levels of vitamins and minerals were compared between HIV positive and negative people, few significant differences were found. [2] One small study found that the CD4 T-cell count of HIV positive people slightly increased after taking a

vitamin and mineral supplement for 12 weeks. [3] All of the HIV positive people in the study were taking ARVs, although they were older generation drugs.

Clearly more studies are needed to fully understand the role of vitamins and minerals in HIV-positive people. However, some Doctors already recommend taking a multivitamin/mineral supplement.

Some vitamins and minerals may also affect certain ARVs, making it a good idea to speak to your doctor if you are thinking of taking any supplements.


Vitamins and minerals are vital for keeping your body healthy. They have a wide range of functions in the body and very low levels can cause deficiencies. Most people will get all the vitamins and minerals they need from eating a balanced diet, but others may need supplements. HIV-positive people who don’t eat a balanced diet may consider a vitamin and mineral supplement.

Want to find out more information?

Detailed information on safe amounts of vitamins and minerals:

Safe upper levels for vitamins and minerals – Expert Group on Vitamins and Minerals (2003)

In-depth guide all about supplements and any benefits or risks they pose:

Supplements: Who needs them? A special report – NHS Behind the headlines (2011)


  1. Krall EA and Dawson-Hughes B. Smoking increases bone loss and decreases intestinal calcium absorption (Feb 1999) J Bone Miner Res 14(2):215-220. 
  2. Drain P et al. Micronutrients in HIV-positive persons receiving highly active antiretroviral therapy (2007) Am J Clin Nutr 85:333-345
  3. Kaiser JD et al. Micronutrient supplementation increases CD4 count in HIV-infected individuals on highly active antiretroviral therapy: a prospective, double-blinded, placebo-controlled trial (15 Aug 2006) 42(5):523-528.

Last updated: 25 October 2012.