MUCH IS THAT?
Nutrient amounts are measured in various units:
g = gram
mg = milligram = of a gram
mcg = microgram = of a gram
IU = international unit
RE = retinol equivalent = the amount of “true” vitamin A in an IU
a-TE = alpha-tocopherol equivalent = the amount of alpha-tocopherol in a unit of vitamin E
TABLE 3-1 Vitamin RDAs for Healthy Adults
| Age (Years) | Vitamin A (RE/IU)† | Vitamin D (mcg/IU)‡* | Vitamin E (a-TE) | Vitamin K (mcg)* | Vitamin C (mg) |
|---|---|---|---|---|---|
| Males | |||||
| 19–30 | 900/2,970 | 15/600 | 15 | 120 | 90 |
| 31–50 | 900/2,970 | 15/600 | 15 | 120 | 90 |
| 51–70 | 900/2,970 | 15/600 | 15 | 120 | 90 |
| 71 and older | 900/2,970 | 20/800 | 15 | 120 | 90 |
| Females | |||||
| 19–30 | 700/2,310 | 15/600 | 15 | 90 | 75 |
| 31–50 | 700/2,310 | 15/600 | 15 | 90 | 75 |
| 51–70 | 700/2,310 | 15/600 | 15 | 90 | 75 |
| 71 and older | 700/2,310 | 20/900 | 15 | 90 | 75 |
* Adequate Intake (AI)
† The “official” RDA for vitamin A is still 1,000 RE/5,000 IU for a male, 800 RE/4,000 IU for a female who isn’t pregnant or nursing; the lower numbers listed on this chart are the currently recommended levels for adults.
‡ The current recommendations are the amounts required to prevent vitamin D deficiency disease; recent studies suggest that the optimal levels for overall health may actually be higher, in the range of 800–1,000 IU a day.
| Age (years) | Thiamin (Vitamin B1) (mg) | Riboflavin (Vitamin B2) (mg) | Niacin (NE) | Pantothenic acid (mg)* | Vitamin B6 (mg) | Folate (mcg) | Vitamin B12 (mcg) | Biotin (mcg)* |
|---|---|---|---|---|---|---|---|---|
| Males | ||||||||
| 19–30 | 1.2 | 1.3 | 16 | 5 | 1.3 | 400 | 2.4 | 30 |
| 31–50 | 1.2 | 1.3 | 16 | 5 | 1.3 | 400 | 2.4 | 30 |
| 50–70 | 1.2 | 1.3 | 16 | 5 | 1.7 | 400 | 2.4 | 30 |
| 71 and older | 1.2 | 1.1 | 16 | 5 | 1.7 | 400 | 2.4 | 30 |
| Females | ||||||||
| 19–30 | 1.1 | 1.1 | 14 | 5 | 1.3 | 400 |
