Why nutrition shapes the hair you see
Hair is built from the inside out. Each follicle is a small, demanding organ that cycles through growth, rest and shedding phases — and that cycle depends on a steady delivery of micronutrients, amino acids and minerals through the bloodstream. When the supply is thin, hair is one of the first tissues the body deprioritises. The result is rarely dramatic. It is usually slower regrowth, more shedding in the shower, a duller surface and a finer ponytail over the years.
This is why nutritional deficiencies can cause hair loss long before they cause obvious clinical symptoms elsewhere. Hair is a sensitive early indicator of how well the body is nourished.
The nutrients most associated with hair loss
The literature on hair and nutrition consistently surfaces the same short list. None of these is a cure on its own — but a sustained gap in any of them can quietly hold hair back.
Iron
Low iron stores (ferritin) are one of the most commonly reported nutritional patterns in people experiencing diffuse hair shedding, particularly in women of reproductive age. Iron supports oxygen delivery to the follicle and the enzymes that drive hair matrix cells.
Vitamin D
Vitamin D receptors are expressed in hair follicles and appear to play a role in the initiation of new growth cycles. Low vitamin D is widespread in northern latitudes and is frequently observed alongside thinning and slower regrowth.
Zinc
Zinc participates in protein synthesis and the repair of hair tissue. Restrictive diets, high stress and certain medications can quietly erode zinc status over time.
Biotin (Vitamin B7)
Biotin is a coenzyme for keratin production. True biotin deficiency is uncommon in a varied diet, but suboptimal intake can still influence hair and nail quality, especially during pregnancy or with certain gut conditions.
Vitamin B12 and Folate
Both are essential for red blood cell formation and the delivery of oxygen and nutrients to the scalp. Plant-forward diets without supplementation are a common source of low B12.
Protein and amino acids
Hair is structurally protein. Persistently low protein intake — often seen in calorie-restricted or highly processed diets — limits the raw material the follicle has to work with.
Selenium, copper and silica
These trace minerals support antioxidant defence and the cross-linking that gives the hair fibre its strength. They rarely act alone but matter as part of a complete picture.
Vitamins for hair growth: what the picture looks like in practice
In day-to-day terms, the people most likely to notice hair changes from dietary gaps are those with repeated dieting cycles, restrictive eating patterns, heavy training loads without matching intake, post-partum periods, peri-menopause, very low-iron or low-B12 diets, and prolonged stress that suppresses appetite and absorption.
The honest answer is that vitamins for hair growth do not "grow new hair" in isolation. They make it possible for the follicle to do its work when conditions allow. The aim is sufficiency, not megadosing.
An inside-out approach to hair longevity
Our perspective is that hair is a long-term tissue and should be treated like one. Outer care — gentle cleansing, scalp circulation, fibre protection — sets the surface conditions. Inner nutrition — adequate protein, the key micronutrients above, and consistent intake over months and years — sets the structural ones. Neither side alone is enough.
This is the foundation of Hair Longevity, the discipline that shapes everything we do at Green Monkey Club AG, and the reason our portfolio is split between outer care and inner nutrition under two complementary brands.
Where Green V fits in
Green V is our inner-nutrition brand, formulated around the micronutrients most relevant to hair over the long term. It is designed as a daily, low-friction baseline — something a thoughtful adult can take consistently for years, not a short cosmetic intervention. It complements, rather than replaces, a varied diet and proper medical guidance for any clinical hair loss.
If you would like to learn more about our standards, sourcing and manufacturing approach, see our Science & Standards page.
A note on medical advice
This guide is educational. Persistent or sudden hair loss can have medical causes beyond nutrition, including thyroid disorders, hormonal changes, autoimmune conditions and medication side effects. If hair loss is significant, sudden or accompanied by other symptoms, consult a qualified physician or dermatologist before making supplement decisions.