Sources: Liver, kidneys, muscle meats, fish, dairy products, meat, and eggs are all good sources of B-12.
Recommended daily intake: Both men and women need 2.0 mcg of B-12 daily. Because B-12 is water soluble, it is constantly lost in urine when not used and a steady supply is needed. B-12 deficiency can lead to a type of anemia, walking and balance problems, sore tongue, weakness, confusion, and in advanced cases, dementia. Pregnant or breastfeeding women should not take more than 2.6 mcg and 2.8 mcg of B-12, respectively. People over the age of 50 may need B-12 supplementation as the body's ability to absorb vitamin B-12 from food sources diminishes.
Function: Vitamin C helps to heal wounds, prevent cell damage, promote healthy gums and teeth, strengthen the immune system, and absorb iron. It also helps neutralize free-radicals in cells that promote aging, fight bacterial infections, and aid in the production of red blood cells.
Sources: Fresh fruit and berries (especially citrus fruits), green vegetables, onions, tomatoes, radishes, and rose hips are all excellent vitamin C sources.
Recommended daily intake: Men and women should each consume at least 60 mg of vitamin C daily. Many things can increase the need of vitamin C in the body, including stress and smoking. For smokers, recommended intake increases to 110 mg for women and 125 mg for men. While not getting enough vitamin C can lead to scurvy, consuming more than 2000 mg on a daily basis can lead to headaches, increased urination, mild diarrhea, nausea, and vomiting. Pregnant and breastfeeding women should not take more than the recommended amounts of Vitamin C.
Function: Vitamin D is important in helping the body use and absorb calcium. It is also necessary in the utilization of phosphorous. Also known as Calciferol, it promotes strong bones and teeth, prevents rickets, supports muscle and nerve function, and, some studies have shown, helps prevent osteoporosis.
Sources: Fortified milk and cereals, eggs, tuna, fish-liver oils, and sun exposure all help the body obtain vitamin D.
Recommended daily intake: Men and women aged 19-50 should consume at least 200 IU of vitamin D on a daily basis. People over the age of 50 should consume at least 400 IU daily, as the body's ability to convert sunlight to vitamin D decreases with age. While too little vitamin D can lead to weakened bones and an increased risk of fractures, too much vitamin D can cause nausea, vomiting, poor appetite, constipation, weakness, and weight loss. Prolonged exposure to too much vitamin D can lead to health problems and toxicity. If you take, antacids, some cholesterol lowering drugs, some anti-seizure medications, or steroids, know that they all interfere with the absorption of vitamin D.