Vitamin A is an essential nutrient that plays a vital role in our health. It’s also known as retinol and can be found in foods like butter, eggs, fish, and dairy products. But did you know that vitamin A is also essential for good bone health?
Even though vitamin A is found in so many of the foods we eat, many people aren’t getting enough of it—and that can lead to bone issues later in life.
Vitamin A deficiency can cause anemia, night blindness, osteoporosis and tooth decay because it helps with the absorption of calcium. Since vitamin A helps us absorb calcium from food sources such as milk products or leafy greens like spinach, it’s important to get enough of this vitamin if you’re trying to achieve healthy bones.
Vitamin A For Bones
Vitamin A is a fat-soluble vitamin that is important to building strong, healthy bones. Both osteoblasts (bone building cells) and osteoclasts (bone breaking down cells) are influenced by vitamin A. Despite its good effects, most clinical research links higher vitamin A levels with lower bone density and fractures
Here are the four vitamins that, in addition to vitamin D, are important to bone heath. The good news is that you can find them in many of the foods you eat.
Vitamin A is a fat-soluble vitamin that is important to building strong, healthy bones. Both osteoblasts (bone building cells) and osteoclasts (bone breaking down cells) are influenced by vitamin A. Despite its good effects, most clinical research links higher vitamin A levels with lower bone density and fractures.
One source of vitamin A is retinol, found in meat and fish, fortified breakfast cereals, and vitamin supplements. Vitamin A is fat-soluble and stored in our livers. So the liver of fish and animals are particularly rich in vitamin A.
Another source of vitamin A is beta-carotene, found in dark green and orange fruits and vegetables. Beta-carotene is generally considered safe. According to the National Institutes of Health, the RDA for men age 19+ is 3,000 International Units (IUs) and 2,330 IUs for women in the same age range.
Too much vitamin A (more than 3,000 mcg or 10,000 IU/day) will give you a headache and has been linked to bone loss. Pay particular attention to this possibility if you eat liver or take supplements.
Sources of vitamin A: Cantaloupe, carrots, cheese pizza, eggs, fatty fish, fat-free milk, kales, liver, mangoes, sweet potatoes, and spinach
Read the Office of Dietary Supplements Fact Sheet on on vitamin A
Vitamin B12 appears to have an effect on bone building cells.
A Tufts University study done by Katherine Tucker and her colleagues showed that low levels of vitamin B12 are linked to a higher risk of osteoporosis in both men and women. Vitamin B12 is found in meat and fish, making vegans, who don’t eat meat or dairy, at risk for bone loss.
People who have had a gastric bypass or have gastrointestinal disorders that cause poor absorption of fat lose the ability to absorb B12. Elderly people in their 80s and 90s may develop changes in the linings of the stomach that prevents them from absorbing iron and B12. In these cases where absorption is an issue, doctors may give injections of B12, bypassing the digestive tract, so patients get the benefits of the vitamin.
Sources of Vitamin B12: Dairy products, eggs, fish, fortified breakfast cereal, meat, milk, poultry, shellfish, supplements
Vitamin C is important for healthy gums and healthy bones. Vitamin C is essential to the formation of collagen, the foundation that bone mineralization is built on. Studies have associated increased vitamin C levels with greater bone density.
Vitamin C is water-soluble and the most common reason for low levels is poor intake. Some people with poor absorption will have lower levels of vitamin C. The elderly who are in nursing homes tend to have lower levels of vitamin C. Smokers also tend to have lower blood levels of vitamin C because their intestines do not absorb vitamin C normally. (Yet another reason to stop smoking!)
Sources of Vitamin C: broccoli, bell pepper, cauliflower, kale, lemons, oranges, papaya, strawberries
how long does vitamin a stay in your system
It depends on how much is there, to a certain extent, and it’s solubility in water. Vitamin C is highly water soluble, and you excrete it in your urine pretty quickly — the half-life (time it takes the concentration to decrease 50%) is about 30 minutes. Vitamin D is fat soluble and has a much longer half-life of about 15 hours — it’s one of the vitamins that people that take supplements sometimes accidentally take toxic doses of (hypervitaminosis A & D are the most common).
Zinc is not a vitamin, but rather a mineral. Zinc has a really long half-life of about 280 days. One needs to be careful not to overdose on Zinc if taking supplements.
Humans are pretty well adapted to the naturally occurring levels of each vitamin in their diet, so supplementation is typically not advantageous and sometimes harmful. The most common deficiency is vitamin D because activation of vitamin D requires skin exposure to ultraviolet light and many people are either mostly covered, live in northern climates, or work indoors.
That depends on the nutrient.
Generally, vitamins that are water soluble are urinated out after the body has as much stored as it can. Vitamin C, for instance, can build up until about 3000mg are stored, which is called “saturation” – and the actual amount needed for saturation can depend on one’s tolerance and current need for it. Fat soluble vitamins build up in fat cells. As a prevention against toxic build-up for these, usually we consume a “precursor” which can be stored safely, and only converted when needed. Some nutrients have interactions with others. Zinc, for instance, is used in the process of healing. However, it is not usually in short supply. So if too much is consumed – for instance when one takes extra during a cold – zinc can block a biochemical process in the body at the site where copper should be used – and thus mess up our immune systems.
Most multivitamins supply a basic daily need of vitamins and minerals. This is way less than toxic doses, for those which you can over do. Most of us don’t need “extra” vitamins, beyond what we eat, but if we tend to skip certain food groups, such as fruit with Vit C, it can be an “insurance” policy against inadequate intake.
My interpretation of your question is how long do excesses of vitamins and minerals provided by supplements stay in your system. In a normally functioning, health body, your intestinal tract reduces absorption of large amounts of vitamins and minerals and so some is lost in the feces, and from what is absorbed, your liver will transform some so they are easier to excrete in your urine along with those that do not need transformation. Depending on what processes are going on in your body, some nutrients are needed in larger amounts so the body will hang on to what it needs. fat soluble nutrients are harder to get rid of than the water soluble ones since we store the fat soluble ones in our livers and fat stores. There are a few water soluble ones that the body holds on to, like B12 and folate, iron and zinc, because of their important roles in metabolism and thus they are recycled more effectively.
Anytime there is a answer on nutrition, especially dietary supplements, I look to see if it is being answered by a Board Certified Clinical Nutritionist. The “fact” that “maximum amount that human cells can absorb is 120–200 mg “ of vitamin C is thirty years old and not relevant today. Firstly, since Ascorbic acid is water soluble. in the past researchers only looked at urine as the excretion route, and did not include the intestines, as we have. Now to answer the question. What is the body mass of the patient? How deficient are they in vitamin C status? How dehydrated are they and, what formulation of vitamin C are they taking?
Vitamin C sequesters free radicals in the body. It is replenished by antioxidant enzymes, and is often used as a reference drug in antioxidant research. Vitamin C’s structure allows it to act on neurology and depression, as well as interact with the pancreas and modulate cortisol. Its antioxidant properties mean vitamin C provides neuroprotective effects and benefits for blood flow. By protecting the testes from oxidative stress, vitamin C can also preserve testosterone levels.
I regularly prescribe 10 grams, 10,000mg of vitamin C to individuals weighing 60 kilos, taking one (1) every hour, on the hour hour with 250 ml of mineral water for circulation problems. It works wonders, especially after they stop taking the ‘water pill’, diuretics.
The saddest part of all this is that I almost daily see sub- clinical symptoms of scurvy, vitamin C deficiency. When I communicate with colleague dentists, they inform me that many patients have bleeding gums.
Multiple vitamins are absorbed ok but because they are in excessive amounts compared to body needs, much is excreted in urine. I taught that multiple vitamins = expensive urine.
Unless ordered by a physician, multiple vitamins are usually not necessary. Exceptions are pregnant women, children and infants and some with illnesses under a doctor’s care.
I’m a nutritionist, dietitian, former University Professor of both; and former bodybuilder turned strength trainer. Not bragging just saying I’ve learned enough to know I never needed a multiple vitamin nor did my 3 sons.
I’ve been curious why vitamin supplements, are held in such high esteem when vitamins are easy to get frequently? The vitamin B family for example is literally everywhere in food. We don’t even need vitamins from food everyday yet we take a pill that often? I decided they were easy and cheap to make and a good salesforce convinced us we needed them.
They even convince one brand is better than another when there is no difference in any brand from cheapest generic to most expensive. A vitamin is a vitamin; thete is no quality difference. It eithet is or is not (same for minerals.) Fortunately, the US knows enough about nutrition now to use their own judgement and just say no if they wish.
Some confuse multiple vitamins with minerals. They point to benefits of iron, calcium for example as a reason to take vitamins when these are not vitamins and not in multiple vitamin supplements.
After a lot of education and gym experience, I know multiple vitamins are not necessary. Instead, I put my money in moderate portions of a variety of good foods — grains, fruits and veggies, dairy or soy alternatives, meat and meat substitutes such as tofu and healthy fats and oils. With wise choices, these have all nutrients not only vitamins.