Your body only requires vitamin B-12 in very small amounts compared to some other nutrients, but it needs it for some critical purposes, including promoting brain and nerve health. Low levels of this vitamin have been linked to serious health problems. Most people can meet their B-12 needs through diet, but you might require supplementation in certain instances to ensure adequate levels.
Recommended Daily Allowance
The recommended daily allowance for B-12 mainly hinges on age. The National Institutes of Health notes the following recommended daily allowance for B12: age 0 to 6 months, .4 mcg; 7 to 12 months, .5mcg; 1 to 3 years, .9 mcg; 4 to 8 years, 1.2 mcg; 9 to 13 years,1.8 mcg; and 14 and older, 2.4 mcg. Pregnant and breastfeeding women have higher requirements -- 2.6 mcg and 2.8 mcg, respectively.
Food Sources
B-12 naturally exists in all animal foods. The richest sources are beef liver and clams -- they give you 800 and 570 percent of your recommended daily intake, respectively. Many foods are also fortified with a variety of B vitamins, particularly breakfast cereals. Claims that you can get B-12 from plant sources like sea vegetables do not hold merit, according to Reed Mangels, Ph.D., R.D., of the Vegetarian Resource Group. She explains the B-12 amounts in these foods are analogues, or inactive forms of the vitamin that your body cannot use. If you follow a vegan diet -- completely devoid of animal products -- or eat animal foods infrequently, include plenty of foods fortified with B-12 or use a supplement.
Considerations for Older Adults
The B-12 naturally found in food is attached to proteins, and your body requires adequate stomach acid to break these proteins down and absorb the vitamin. The Beth Israel Deaconess Medical Center notes many older individuals lack adequate production of stomach acid, which explains the prevalence of B-12 deficiency in this population. The NIH recommends anyone over 50 eat lots of fortified foods or use a supplement to meet B-12 needs.
Supplementation Guidelines
If you choose B-12 supplementation as your primary means of meeting your needs, you must be consistent. Even though supplements often contain much more than the daily recommended intake, your body only absorbs a fraction of it. If you take a 500 mcg supplement, this does not mean you just took enough to meet your B-12 needs for the next 208 days. According to the NIH, your body only absorbs about 10 mcg of a 500 mcg supplement. The more you take at once, the less your body absorbs. Mangels recommends supplementing with 5 to 10 mcg daily or 2,000 mcg once a week.
Member Comments