How does fruit juice boost immune system (when sick)?

My parents used to give me glasses of fruit juice when sick so that my immune system gets boosted. That was a common practice within the family and I guess many people do it.

But does immune system gets boosted by fruit juices? Does it help even more when we are sick? If so, why does it help more when sick?

Keeps you hydrated and provides sugar & nutrients while being easier to take down than solid food if you’re feeling unwell, I can’t think of any downsides to it, it’s not going to help you develop antibodies any quicker though.

It’s basic nutrition, that’s all. There’s nothing special about it that affects an otherwise normal immune system, despite all the hype about ‘boosting’ it.

In short, it’s no better for you than other basic food/drink.

You can *support *your immune system but you can’t really boost it in spite of the hype. Poor nutrition can depress it, but if you have good nutrition, manage stress, exercise, etc., then your immune system will function at its best. (The word “boost” is also used in this cite but if you read the material you’ll see that the word is not used in the same way that it’s used to sell supplements.)

If you had a vitamin C deficiency, orange juice or other fruit juices might “boost” your immune system from a depressed level towards something more normal, but for a healthy person, fruit juice won’t help your immune system fight it off if you get sick.

Fruit juice contains vitamin C … according to Linus Pauling vitamin C cures everything … this claim has been debunked but the urban legend continues …

Delicious is correct, those of us with crappy diets need to eat good wholesome foods when we’re sick as to provide the nutrients needed to make our anti-bodies … and vitamin C is kinda sorta tough to get enough of with the typical American crappy diet … so rather than a mono-nutrient supplement, better to eat something rich in vitamin C thus also getting a number of other nutrients your body needs when it’s sick …

Notwithstanding “Vitamin C Is an Essential Factor on the Anti-viral Immune Responses through the Production of Interferon-α/β at the Initial Stage of Influenza A Virus (H3N2) Infection”

The word “boost” is meaningless marketing, legally, and should be interpreted as a complete nullity.

Vitamins A and D are apparently involved in turning on immune system response.

See Vitamin effects on the immune system: vitamins A and D take centre stage - PMC

However, this may be more of an off switch - if suffering mulnutrition, don’t waste nutritition on futile fighting of minor afflictions.

Vitamin C is required to create collagen . your cold and pneumonia has injured quite a lot of membrane …which requires collagen to repair.

One reason doctors say that vitamin pills dont help a lot, is that there is no where to store the vitamins.

Does it get stored in fat ? it seems that fatty foods and meat provide vitamins. carnivores get vitamins…

So perhaps your beauty sleep is a real thing, as perhaps with the intestines depleated of glucose/energy, the body starts breaking down fat, releasing energy AND vitamins.

A small dose may be stored in the time before the kidney wipes it away.

However strong vitamin pills are a waste, as the kidneys just send the extra level of vitamins to the bladder before the body can make a better use of them (and before they can be stored in fat or in the liver. eg dogs liver are full of vitamin A… perhaps ready for the time they get sick by eating diseased raw meat … vitamin A shot released and so immune system on full… )

It was vitamin C. My mother believed it too and did it. Of course it hydrates. So does chicken soup and it has no sugar.

Yes, you need these vitamins–but once you have enough, adding more doesn’t “boost” your immune system.

Some vitamins, like A, D, E, and K, are fat-soluble and are stored. C and B complex vitamins are water-soluble and can’t be stored.