Vitamins: Key Pieces of Your Health

By Dr. Isaac Eliaz

When it comes to daily vitamin requirements, a number of essential vitamins are recommended to maintain overall health and well-being. When you feed your body with adequate levels of these essential nutrients through diet and/or supplementation, you promote vitality, contribute to longevity and help prevent disease. Here is an overview of seven key vitamins that offer support for a number of critical body functions and help promote total-body health and wellness.

The dosages listed below include Recommended Dietary Allowances (RDA) as set by the Food and Drug Administration; however, be aware that they represent the minimum daily amounts required to avoid serious deficiency of each nutrient. For many nutrients, the therapeutic dosages necessary to achieve optimal health and avoid illness are much higher, but the toxicity levels for many of these nutrients must also be kept in mind. Therefore, it is always advisable to consult with your health care provider before starting any nutritional program, particularly if it involves increasing your intake of specific nutrients.

Vitamin A

Vitamin A plays an important role in vision, bone growth, reproduction, and cell division. Adequate amounts of vitamin A help to regulate the immune system and protect against infections by producing the white blood cells that destroy harmful bacteria and viruses. Vitamin A is known to be beneficial for eye health, as it is absorbed in the form of retinol, which is one of the most active forms of vitamin A that produces pigments in the retina of the eye and helps promote good vision. This type of vitamin A is found in foods such as eggs, milk and liver.

Another type of vitamin A is called a carotenoid, which is found in plant-based foods and includes beta-carotene, alpha-carotene and beta-cryptoxanthin. These forms of vitamin A can offer protection against cataracts, macular degeneration, cardiovascular problems, and other health conditions associated with oxidative damage. In addition to serving as powerful antioxidants, carotenoids promote the growth of healthy cells, while inhibiting the growth of unhealthy ones. A common dosage for vitamin A is 2,500 IUs a day, with additional 2,500-7,500 IUs a day as beta-carotene. In rare cases, high levels of vitamin A can cause toxicity, and is therefore no longer given at high dosages such as 100,000 IUs a day on a long-term basis.

Dietary sources: Carrots, sweet potatoes, pumpkin, eggs, milk.

Vitamin B₁₂

Another valuable vitamin for overall well being is vitamin B₁₂, which helps the body make healthy blood cells and maintains a healthy nervous system and brain function. Vitamin B₁₂ is often found in supplements that are combined with other B vitamins in a vitamin B complex formulation, but is also rich in animal food products such as meat, shellfish, milk, cheese, and eggs. When part of a healthy diet, vitamin B₁₂ not only contributes to healthy blood cell formation, but also helps maintain healthy nerve cells and DNA. Since the body is able to store vitamin B₁₂ over time, nutritional deficiency of this particular vitamin is rare, but elderly individuals and strict vegetarians whose diets are lacking animal products are at the highest risk of developing a deficiency.

Vitamin B₁₂ is one of the most under-dosed vitamins, but as a water-soluble vitamin, it is very safe. Adults need at least 2.4 micrograms of vitamin B₁₂ on a daily basis, but up to 5 mg a day of the vitamin can be taken orally. It is often used in injections, chronic pain, fatigue, neuropathies, jet lag and other common ailments. There are two common forms of B₁₂, cyianocobalamine and methylcobalamine. While both forms offer a range of health benefits, methylcobalamine is preferred for treating central nervous system symptoms.

Dietary sources: Fish, meat, poultry, eggs, milk, and milk products.