Immune System

Immune System Supplements: Vitamin C, Vitamin D, Zinc and Selenium

Nutrients with authorised claims: vitamin C, vitamin D, zinc and selenium contribute to the normal function of the immune system. The same applies to vitamin A, vitamin B6, vitamin B12, folate and copper. These claims apply only to products that provide at least 15% of the nutrient reference value (NRV) per daily dose — always check each product's table.

Vitamin C: besides the immune system, vitamin C contributes to normal collagen formation for the normal function of skin, to the protection of cells from oxidative stress and to the reduction of tiredness and fatigue. You will find 1000 mg capsules, liposomal vitamin C and powders in the Vitamin C collection.

Vitamin D3 (with or without K2): vitamin D contributes to the normal function of the immune system and to the maintenance of normal bones; vitamin K contributes to the maintenance of normal bones. Doses range from 1000 to 5000 IU — above 4000 IU (100 µg) a day the tolerable upper intake level set by EFSA is exceeded, so those doses should only be used under medical supervision. See every option in Vitamin D.

Zinc and selenium: zinc and selenium contribute to the normal function of the immune system and to the protection of cells from oxidative stress. Mind the dose: the EFSA tolerable upper intake level is 25 mg/day for zinc and 255 µg/day for selenium. Compare forms and doses in Zinc.

Multivitamins and other products: a multivitamin combines several of these nutrients in a single dose. On this page you will also find probiotics, bovine colostrum, garlic oil, beetroot and greens powders — these ingredients have no authorised health claims in the European Union, so we describe them only by origin, form and amount per serving.

Frequently asked questions

When should I take vitamin D? Take it with a meal that contains fat, at the dose stated on the label. The skin makes vitamin D with sun exposure, which is lower in autumn and winter.

Can I combine several products? Add up the vitamin D, zinc and selenium doses from every product you take so that you do not exceed the upper levels. Food supplements should not be used as a substitute for a varied and balanced diet and a healthy lifestyle. Do not exceed the recommended daily dose and consult your doctor before use if you are pregnant, breastfeeding, taking medication or have a medical condition.

Buy in Portugal: At Nutri9 you can buy online with delivery across Portugal or visit our physical shop in Malveira. On each product page you will find the price, the full composition, the daily dose and the manufacturer's directions for use.