Vitamin therapy — what it means, when it makes sense and why blood tests come first

Vitamin therapy means giving vitamins and minerals for a therapeutic purpose — by mouth, intramuscularly or intravenously — and it has a clear medical basis when a deficiency has been confirmed by blood tests. For most deficiencies, the oral form is the first option when it is enough; an injection or an IV drip is justified in specific situations, not as a rule.

What the term actually means

"Vitamin therapy" is not a medical specialty, nor a standardised procedure. It is an umbrella term, used just as readily for a vitamin B12 treatment prescribed by a family doctor (GP) as for a vitamin IV drip given without any blood test.

That is why, before any discussion of route of administration or price, it is worth separating three situations that carry the same name but have very different levels of evidence.

Three situations, the same name

Correcting a confirmed deficiency. Blood tests show a low level — of vitamin D, vitamin B12, iron — and there is a cause or context that explains it. Here vitamin therapy is medical treatment, with solid evidence.

Supplementation in situations of known risk. People who do not get enough from their diet, who follow very restrictive diets, who have a poor appetite or who avoid certain food groups, for example on a vegan diet. Here supplementation can be reasonable, most often by mouth.

Administration without a deficiency, for general wellbeing. Tiredness, stress, "a bit of maintenance". This is the situation with the least evidence, and precisely the one most often promoted.

Why blood tests come first

The symptoms for which people look for vitamin therapy — tiredness, poor concentration, hair loss, cramps — are non-specific. They occur in vitamin deficiencies, but also in anaemia, thyroid disorders, sleep disorders, depression, or simply after a very demanding period.

Without blood tests you do not know whether you have a deficiency, and if you do, you do not know how large it is. A few concrete examples:

• vitamin B12 — the body keeps stores 1,000–2,000 times larger than the daily intake, so the symptoms of a deficiency may only appear after several years. Deficiency is common in older people and can occur in those taking metformin or medicines that reduce stomach acidity;
• vitamin D — it accumulates in the body, so a high dose given "preventively" without a measured level can lead to over-correction. Details in the article on injectable vitamin D3;
• iron — a single value is not enough; ferritin, the full blood count and, where relevant, C-reactive protein are interpreted together. See what low serum iron means.

And a fact that contradicts the marketing: the Office of Dietary Supplements of the US National Institutes of Health states explicitly that vitamin B12 does not increase energy or endurance in people who get enough B12 from their diet.

Oral first, when it is enough

For most people with a confirmed deficiency, the oral form works. The best-studied example is vitamin B12.

The 2018 Cochrane review compared oral with intramuscular vitamin B12 in three randomised trials with 153 participants. In the trials using 1,000 µg a day by mouth, normalisation of the B12 level was similar to injection, and oral treatment cost less. The certainty of the evidence is low, because the trials are few and small — but the direction is clear.

The injectable or intravenous route makes sense in specific situations:

• malabsorption — inflammatory bowel disease, coeliac disease, bariatric surgery, pernicious anaemia;
• documented intolerance of the oral form;
• difficulty sticking to a daily treatment;
• the need to correct a significant deficiency within a defined time frame.

If none of these applies to you, the tablet is simpler and cheaper. We say so even though we provide the other option.

And vitamin IV drips without a deficiency?

The most cited controlled study on the subject tested the famous "Myers' Cocktail" — an intravenous combination of micronutrients — in 34 adults with fibromyalgia, with one infusion a week for eight weeks. The control group received infusions of lactated Ringer's solution.

The result: both groups felt better, and the differences between them were not statistically significant, partly because of a large placebo response. The authors concluded that effectiveness compared with placebo remains uncertain. More on this: what Myers' Cocktail is.

What an IV drip does for certain: it delivers a known dose, predictably, and provides fluids. For some substances, such as vitamin C, it allows concentrations that the oral route cannot reach — explained in the article on vitamin C ampoules. That these translate into a clinical benefit in a person without a deficiency is a separate claim, which the data do not solidly support.

Questions to ask anyone who offers you vitamin therapy

Which deficiency do I have, and which blood test is the claim based on?

Why not the oral form? Is there a concrete reason — malabsorption, intolerance, urgency — or just a preference?

What dose am I getting, and of which substances? The composition should be written down, not "a cocktail".

How many sessions, and why this number? A course should have a justification, not just a package price.

How will we know if it worked? For a deficiency, the answer is a follow-up blood test, not just how you feel afterwards.

If you get no answer to the first two, the vitamin therapy on offer most likely belongs to the third category above.

The risks, in brief

• fat-soluble vitamins accumulate — vitamin D and vitamin A can reach toxic levels;
• combining sources — fortified foods, a multivitamin, an IV drip — can exceed the upper limits without you realising;
• in smokers and former smokers, high doses of beta-carotene and vitamin A should be avoided;
• any intravenous administration involves a cannula, a small risk of reaction and medical staff present.

What vitamin therapy looks like at Synerva

The protocols in our catalogue, with their composition and price:

There are also two courses: Immunity course — 4 Immunity Boost sessions, 1,990 RON (2,400 RON separately) and Complex B forte course — 4 Complex B forte sessions, 2,190 RON (2,600 RON separately).

The number of sessions in a course does not mean a course is necessary: if you need one, how many sessions and at what interval is decided at the assessment. The medical assessment is included. If you have recent blood tests, bring them; if you do not and your situation calls for them, we tell you what to do first. And if the conclusion is that a tablet is enough for you, that is what you get.

More: vitamin therapy and vitamin IV drips.

Sources

Wang H. et al. — Oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency, Cochrane Database of Systematic Reviews, 2018.

National Institutes of Health, Office of Dietary Supplements — Vitamin B12: fact sheet for consumers: stores, at-risk groups, interactions, no effect on energy without a deficiency.

National Institutes of Health, Office of Dietary Supplements — Multivitamin/mineral supplements: fact sheet for consumers: who may benefit, upper limits, beta-carotene in smokers.

Ali A. et al. — Intravenous micronutrient therapy (Myers' Cocktail) for fibromyalgia: a placebo-controlled pilot study, Journal of Alternative and Complementary Medicine, 2009.

For information only. It does not replace a medical consultation; interpreting blood tests and choosing the route of administration rest with the doctor.