How is vitamin C related to skin?

Several nutrients carry skin-related statements — vitamin A, riboflavin, biotin and zinc among them. Vitamin C's is the one that names collagen formation specifically.

What statements are recognised?

The annex to Thai Ministry of Public Health Notification No. 447 (B.E. 2566) states that vitamin C contributes to normal collagen formation for the normal function of skin, with the same construction appearing for bones, gums, teeth and cartilage.

It also recognises that vitamin C contributes to the protection of cells from oxidative stress, to the normal function of the immune system, and that it increases iron absorption.

Why is vitamin C tied to collagen?

The body builds collagen from amino acids in a series of steps, and vitamin C takes part in one of them. That is why the statement is worded as it is.

How much per day?

Recommended intakes set by the US National Academies' Food and Nutrition Board, as published by the NIH Office of Dietary Supplements, are 90 mg a day for adult men and 75 mg for adult women. The tolerable upper intake level is 2,000 mg a day.

Where does it come from in food?

Many Thai fruits are rich in it. Indian gooseberry is the highest per 100 g, then guava, then orange, papaya and pineapple. Among vegetables, sweet pepper, broccoli and Chinese kale.

Vitamin C degrades with heat and storage, so fresh fruit supplies more.

How do the forms in products differ?

Ascorbic acid is the basic form. Calcium ascorbate is less acidic. Vitamin C from acerola comes from fruit.

Labels usually state "provides vitamin C X mg", and that is the figure to compare.

What if you take too much?

Vitamin C is water-soluble and the excess is excreted. Very large single amounts leave some people uncomfortable, so splitting into two occasions is usually easier.

Dietary supplements are not intended to prevent, treat or cure any disease.