If the man who discovered vitamins, a chemist called Casimir Funk, had been a bit more egotistical we might now be fighting over Funkies. The sheer absurdity of the name might take some of the steam out of a battle that has become ridiculously polarized.
On one side are attacks such as that heralded on the cover of the current edition of Consumer Reports warning of ‘10 Surprising Dangers’ from vitamins. These include overdosing if you take more than the recommended daily amount (RDA).
UK doctors and dieticians might not go so far, but many will advise against supplementation on the grounds that all we need is a ‘healthy balanced diet’.
Yet the number of people clearly damaged by vitamins is vanishingly small and thousands of studies have reported benefits. Indeed, we may need them more as we age and begin to absorb nutrients less effectively from diets that may, anyway, be poorer.
Two more general points. Many negative trials have tested vitamins in isolation as if they were drugs. But they are team players. To get the most out of vitamin C, you need to combine it with vitamin B2. If you are taking vitamin D for bone health, you should also take the mineral magnesium.
Then there are the vitamin muggers. Medical skeptics often warn against supplements on the grounds they can interfere with drug actions. What they never consider are the ways drugs can block or reduce availability of vitamins.
So here is the definitive guide to ones you need and why.
Found in the liver of domestic animals and fish, as well as vegetables such as carrots, broccoli and spinach. It is needed for eye, bone and skin health.
The RDA is 900 mcg (micrograms) and going much above that is not recommended. If you are supplementing, it is usually taken as part of a multivitamin, unless you need more for a skin problem.
There has been a link with cancer. The body turns beta-carotene (contained in colored fruit and vegetables like carrots) into vitamin A. One study found that giving just a synthetic beta-carotene supplement to smokers increased their risk of developing lung cancer. Reports didn’t make it clear this only happened if you kept on smoking.
Found in most unprocessed foods, but particularly in liver, turkey and tuna. Plant sources include potatoes, bananas, lentils and molasses. It is actually a family of eight distinct vitamins, including niacin, riboflavin, B6 and B12 (which are usually found together).
These speed up chemical reactions and are vital for healthy skin and muscle tone, proper working of the nervous system and cell growth. The three most widely used are niacin (B3) with an RDA of 16 mg (milligrams), B12 with an RDA of 2.4 mcg, and folate, with an RDA of 400mcg.
In very high doses (1,000mg a day) niacin brings down harmful LDL cholesterol and raises protective HDL. Recent research on animals suggests it may be useful for combating superbugs such as MRSA.
As you get older, you absorb B12 less well, making deficiency more likely. This can lead to muscle and nerve problems. The diabetes drug metformin also reduces the availability of B12 in the body.
B vitamins could cut your Alzheimer’s risk. In 2010, a controlled trial using very high doses of B12, B6 and folate was shown to reduce brain shrinkage in people with mild cognitive impairment (which can lead to Alzheimer’s). This double blind trial, backed up with brain scanning, hasn’t been repeated.
Found in lots of fruits and vegetables. The richest source is the Kakadu plum, with 3000mg per 100gms. Oranges have 50mg per 100 grams. The RDA is 90mg a day. It’s an anti-oxidant, vital for neutralizing damaging free radicals.
It is also needed for various enzyme reactions in the body to work, including collagen production. This is why it prevents scurvy, boosts immunity and is essential for the healing of wounds.
It is often taken in much higher doses than the RDA with no good evidence of serious side effects. One recent trial by a major American hospital found that doses of 500mg a day can lower blood pressure.
A controversial cancer treatment involves giving very high doses intravenously. It is effective in animals, and now being tested on humans. Diuretics, the drugs given to treat high blood pressure, raise the rate at which several minerals and vitamins are peed out of the body, including vitamin C.
Found in fairly small amounts in fatty fish, eggs and beef liver. It’s mainly made in your skin by the UV B rays in sunlight. Until fairly recently, doctors thought it was only needed for healthy bones and teeth and that 200-400 IU (5 to 10 mcg) a day was enough, while 1,000 IU (25mcg) could be dangerous.
That is changing as low levels in the blood are increasingly linked to a raised risk of a variety of chronic disorders: cancer, heart disease, diabetes (types 1 and 2) and multiple sclerosis.
By the end of winter, most people in the UK don’t have much more than 10ng/ml (nanograms per milliliter) of vitamin D in their blood – just about enough to protect their bones but way below levels of 30+ that exists in the blood of people at lower risk of cancer and heart disease. Taking 1,000 IU, which many experts now consider safe, pushes up your blood levels by about 10ng/ml. Some American experts claim 4,000IU (1,00mcg) is safe.
Found in foods such as asparagus, avocado, eggs, milk, nuts, seeds and green leafy vegetables. Like A and D, it is a fat-soluble, and it’s an antioxidant that, among other things, damps down dangerous free radicals that can make fat go rancid. Like the B vitamins it’s also a family: alpha, beta, gamma, and delta.
Studies some years ago suggested that it cut heart disease risk. More recently, the reverse was discovered. However, the latter trials were all done on heart patients taking statin drugs, which stop the body making an enzyme and antioxidant called CoQ10 that vitamin E needs to work properly.
Recent research has discovered that taking more than the RDA helps with several disorders, including fatty liver disease and lung cancer.
Although there are other vitamins, those covered above are the essential groups. Unless, of course, one counts ‘F’, which stands for Funkies…