Best ingredients for immune

The form of vitamin D the body makes from sunlight and the most effective supplemental form for raising blood levels.

Typical: 1,000–2,000 IU

Ascorbic acid is the reference form of vitamin C and the most common form in supplements; NIH ODS notes its bioavailability equals that of vitamin C naturally present in food.

Typical: 250–1,000 mg

A generic placeholder for a multi-strain probiotic blend, typically combining several Lactobacillus and Bifidobacterium species and sometimes Streptococcus thermophilus or a Bacillus spore.

Typical: 10–50 B CFU

LGG (Lactobacillus rhamnosus GG, ATCC 53103) is the single most studied probiotic strain, isolated in 1985 and since reclassified as Lacticaseibacillus rhamnosus.

Typical: 1–10 B CFU

Bifidobacterium animalis subsp.

Typical: 1–10 B CFU

An extract of black elderberry fruit standardized to anthocyanins, the dark purple pigments, and one of the most popular immune-season botanicals.

Typical: 300–1,200 mg

The most common zinc salt in multivitamins, lozenges, and immune products, containing about 14.3% elemental zinc.

Typical: 10–25 mg

An extract of the aerial parts and root of purple coneflower, the classic North American immune herb.

Typical: 300–1,500 mg

The most abundant free amino acid in blood and muscle and a primary fuel for intestinal and immune cells.

Typical: 5–10 g

Saccharomyces boulardii is a probiotic yeast rather than a bacterium, originally isolated from lychee and mangosteen skins.

Typical: 5–10 B CFU

A generic greens blend is a placeholder for the dried plant powders typical of greens products: cereal grasses such as wheatgrass and barley grass, spirulina and chlorella, leafy vegetables like spinach and kale, and often fruit or vegetable extracts.

Typical: 3–10 g

The organic selenium form found in Brazil nuts, grains, and selenium yeast, in which selenium replaces sulfur in the amino acid methionine.

Typical: 50–200 mcg

Lactobacillus acidophilus is the most widely recognized probiotic species and a staple of yogurt cultures and multi-strain capsules.

Typical: 1–10 B CFU

Zinc chelated with picolinic acid, a tryptophan metabolite that is proposed to aid mineral transport across the gut wall.

Typical: 10–25 mg

Bacillus coagulans is a spore-forming, lactic-acid-producing bacterium whose spores survive stomach acid, heat, and dry storage far better than vegetative Lactobacillus cells.

Typical: 1–2 B CFU

Bifidobacterium longum is one of the dominant bifidobacteria of the adult human colon.

Typical: 1–10 B CFU

An acetylated form of the amino acid cysteine that is the rate-limiting precursor for glutathione, the body's principal intracellular antioxidant.

Typical: 600–1,800 mg

Reishi is a woody polypore used for centuries in East Asian herbal traditions and now sold mainly as a hot-water or dual extract of the fruiting body.

Typical: 1,000–1,500 mg

Lactobacillus reuteri is a native human gut and breast-milk organism, now classified as Limosilactobacillus reuteri.

Typical: 0.1–1 B CFU

The root of Asian ginseng, standardized to ginsenosides, used in energy, fatigue, and vitality products.

Typical: 200–400 mg

Zinc chelated with two glycine molecules, sold as a gentle, well-absorbed form for people who get nausea from zinc salts.

Typical: 10–25 mg

Cordyceps militaris is the cultivated, fruiting-body species that has replaced wild Cordyceps sinensis in most supplements because it grows on grain or liquid substrate at scale and contains measurable cordycepin.

Typical: 1,000–3,000 mg

Cranberry extract is prepared from the whole fruit or juice of Vaccinium macrocarpon and is characterized by A-type proanthocyanidins (PACs) that are studied for anti-adhesion activity against bacteria in the urinary tract.

Typical: 250–500 mg

Retinyl palmitate is an ester of retinol and the most common preformed vitamin A used in supplements and multivitamins.

Typical: 750–1,050 mcg

Lactobacillus plantarum is a versatile lactic acid bacterium found in fermented vegetables and sourdough, now classified as Lactiplantibacillus plantarum.

Typical: 1–10 B CFU

Quercetin dihydrate is the standard crystalline form of the flavonol quercetin, typically extracted from Sophora japonica flower buds and supplied at 95% or higher purity.

Typical: 500–1,000 mg

An essential amino acid that is limiting in grain-based diets and is needed for collagen cross-linking, carnitine synthesis, and calcium handling.

Typical: 1,000–3,000 mg

Spirulina is a dried cyanobacterium (Arthrospira platensis or A.

Typical: 1–5 g

Chemically identical cholecalciferol extracted from lichen rather than sheep's wool lanolin, which lets a product carry vegan and vegetarian claims while keeping the D3 form that raises and holds serum 25(OH)D better than D2.

Typical: 1,000–2,000 IU

Bifidobacterium infantis, now classified as B.

Typical: 1–10 B CFU

Aged garlic extract is produced by soaking sliced garlic in aqueous ethanol for many months, a process that converts harsh, unstable sulfur compounds into odorless, water-soluble ones such as S-allylcysteine.

Typical: 600–1,200 mg

Bifidobacterium bifidum is a mucin-degrading species that is abundant in breast-fed infants and declines with age.

Typical: 1–5 B CFU

Black seed oil is cold-pressed from Nigella sativa seeds, a spice with a long history of traditional use across the Middle East and South Asia.

Typical: 500–2,000 mg

Cod liver oil is pressed from the livers of Atlantic cod.

Typical: 1,000–2,000 mg

A zinc salt of citric acid with a relatively high zinc content of about 31%, giving it a compactness advantage over gluconate and picolinate.

Typical: 10–25 mg

Sodium ascorbate is the sodium salt of ascorbic acid.

Typical: 250–1,000 mg

Beta-carotene is an orange plant pigment that the body can split into retinol as needed, which is why it is called provitamin A.

Typical: 3–15 mg

Copper chelated with two glycine molecules, supplying about 25% elemental copper in commercial grades.

Typical: 0.5–2 mg

Lactobacillus casei is a lactic acid bacterium closely related to L.

Typical: 1–10 B CFU

The densest zinc source at about 80% elemental zinc, which is why it is the default in multivitamins and low-cost tablets where space is tight.

Typical: 10–25 mg

Galactooligosaccharides are chains of galactose units produced enzymatically from lactose, which makes them structurally similar to some of the oligosaccharides in human milk.

Typical: 2.5–5 g

Turkey tail is a thin, fan-shaped polypore whose protein-bound polysaccharides (PSK and PSP) have been studied for decades in Japan and China as adjuncts in oncology settings.

Typical: 1,000–3,000 mg

Olive leaf extract is prepared from the leaves of Olea europaea and standardized to oleuropein, the bitter secoiridoid that also gives olive oil part of its character.

Typical: 500–1,000 mg

Chaga is not a true fruiting body but a sclerotium, a dense black mass that grows on birch trees.

Typical: 500–1,500 mg

A copper salt of gluconic acid, about 14% elemental copper, and one of the most widely used copper sources in multivitamins because it is water soluble, inexpensive, and has a long safety record.

Typical: 0.5–2 mg

D-mannose is a naturally occurring simple sugar related to glucose, found in cranberries and other fruits and made commercially from corn or wood sugars.

Typical: 1–2 g

A generic fruit and vegetable blend is a placeholder for the dried powders and juice concentrates of fruits, berries, and vegetables that appear in multivitamins, greens products, and whole-food-positioned formulas.

Typical: 1–5 g

Oregano oil is the steam-distilled essential oil of Origanum vulgare, standardized to carvacrol, its dominant phenolic compound, at around 70 percent.

Typical: 150–300 mg

An inorganic selenium salt that is about 46% selenium by weight, inexpensive, and readily converted to selenide for selenoprotein synthesis.

Typical: 50–200 mcg

A leaf extract of tulsi, an aromatic basil revered in Ayurvedic tradition and used in modern formulas as a gentle adaptogen for stress and metabolic balance.

Typical: 300–1,000 mg

DE111 is a trademarked strain of Bacillus subtilis, a spore-forming soil and gut organism, supplied by Deerland (now part of ADM).

Typical: 1–5 B CFU

Ergocalciferol is the plant and fungal form of vitamin D, produced by UV irradiation of ergosterol from yeast or mushrooms.

Typical: 400–2,000 IU

Xylooligosaccharides are short chains of xylose produced by enzymatic breakdown of xylan from corn cobs or other plant cell walls.

Typical: 1,000–2,000 mg

A shrub root from Siberia and northern Asia, marketed for decades as Siberian ginseng even though it is not a true Panax species.

Typical: 300–1,200 mg

Quercetin phytosome is quercetin complexed with sunflower lecithin phospholipids, sold as Quercefit by Indena.

Typical: 250–500 mg

Calcium ascorbate is the calcium salt of vitamin C, commonly supplied as the dihydrate.

Typical: 250–1,000 mg

The root of a legume used for centuries in Chinese herbal practice as a tonic, now included in immune, energy, and longevity formulas.

Typical: 250–1,000 mg

Nettle leaf is the dried aerial part of Urtica dioica, a nutrient-dense green used in traditional European herbalism and in modern seasonal and immune formulas.

Typical: 300–600 mg

Shiitake is the world's second most cultivated edible mushroom and a source of the beta-glucan lentinan, eritadenine, and ergothioneine.

Typical: 1,000–2,000 mg

A complex of zinc with the amino acid L-methionine, best known under the OptiZinc trade name, carrying roughly 21% elemental zinc.

Typical: 10–25 mg

Maitake is a clustered, edible polypore whose proprietary beta-glucan extract, D-fraction, has been studied in small oncology and immunology trials, including a phase II study in myelodysplastic syndromes.

Typical: 500–2,000 mg

Slippery elm is the inner bark of Ulmus rubra, a North American tree.

Typical: 400–1,500 mg

Marshmallow root is the dried root of Althaea officinalis, a European plant unrelated to the confection that borrowed its name.

Typical: 500–1,500 mg

Ascorbyl palmitate is an ester of ascorbic acid and palmitic acid that is soluble in fat rather than water.