The safety of micronutrients – Part 2: water-soluble vitamins
Insufficient and excessive consumption of nutrients can both increase the risk of damage to health. As intake is increased, the risk of developing a harmful nutrient deficiency falls until the intake reaches an amount that is regarded as adequate (recommended daily amount). Above this amount (tolerable upper intake level or UL) toxic effects may be seen that once more increase the risk of damage to health. How the body reacts to the consumption of specific micronutrients depends on the dosage and on the consumer’s baseline nutrient status. If nutrient levels are already high, increasing consumption is likely to increase the risk of toxicity. With vitamins as with all nutrients: more is not always better. This also applies to water-soluble vitamins, although these do not accumulate in the body to the same degree as the fat-soluble vitamins (see also The safety of micronutrients – Part 1: fat-soluble vitamins).