Vitamin B1 Thiamin DRI

Vitamin B1 Thiamin DRI

In 1998 the National Academy of Sciences Institute of Medicine released the following new Recommended Dietary Allowances (RDAs) for thiamin for all individuals starting at 1 year of age and Adequate Intake (AI) levels for infants less than 1 year old.

                                       Group                                  Thiamin AI

                                    0-6 months                             200 mcg
                                    6-12 months                           300 mcg

                                       Group                                Thiamin RDA

                                    1-3 years                                500 mcg
                                    4-8 years                                600 mcg
                                    9-13                                        900 mcg
                                    Males, age 14+                       1.2 mg
                                    Females, age 14+                   1.1 mg
                                    Pregnant females                    1.4 mg
                                    Lactating females                    1.5 mg
The reason increased amounts are recommended for pregnant and lactating women is that they need the B vitamins for themselves but also for the proper growth and development of their unborn or newborn child. The total amount of thiamin required for infants is less than for older individuals.
Thiamin requirements are based on a combination of factors. A healthy individual requires about 0.5 mg of thiamin for every 1,000 calories consumed. The RDAs indicated here are not very high, and individuals who take vitamin B supplements typically take much higher amounts. Since taking in more than the minimum requirement cannot hurt you, some experts recommend about 10 mg/day as extra insurance. We are neither agreeing nor disagreeing because every individual is different. Your personal physician who is familiar with your medical history and current health status is the one who can best advise you whether thiamin supplementation is necessary and, if so, how much to take and for what length of time.

Upper Tolerable Limits

Unlike with many other nutrients, there is no evidence that thiamin can produce symptoms of toxicity, even at very high doses. Accordingly, the Institute of Medicine has not established a Tolerable Upper Intake Level (UL) for this vitamin.