About ten years ago, there was major clamor about the importance of Vitamin D. Many people were touting it as a preventive for several diseases and a cure for others. Teams of researchers were feverishly investigating whether vitamin D could really live up to the many claims being made about it. Some even said Vitamin D was one of the more important medical subjects of the 21st century, and get on board because it’s going to be the next big thing.
Well, over the ensuing years, Vitamin D has taken on new significance and importance, but it has not proven to be the cure-all for major diseases as was originally thought. Medicine and medical care have not been revolutionized by a deeper understanding of Vitamin D nor has treatment and prevention of disease been greatly impacted by its use.
Known colloquially as “the sunshine vitamin,” Vitamin D is produced when your skin is exposed to ultraviolet light, ie. sunlight. UV rays in sunlight cause your skin to make vitamin D. The amount produced is dependent on the season of the year, the time of day, the amount of cloud cover and air pollution, and your proximity to the equator. A direct correlation exists between Vitamin D production and sunlight—more sun exposure for longer periods equals greater Vitamin D amounts.
Our diet is the “best way to get enough Vitamin D.” A variety of healthy foods from all food groups supply us with Vitamin D, but dietary intake alone is inadequate for our total need. The addition of UV light exposure complements dietary intake in most people, but some will still need supplementation. Foods high in Vitamin D content are as follows:
1. Salmon
2. Sardines and Herring
3. Cod liver oil
4. Canned Tuna
5. Oysters
6. Shrimp
7. Egg yolks
8. Mushrooms
9. Milk, fortified with D
10. Orange Juice fortified with D
11. Cereal, Oatmeal
I don’t know about you, but my intake of sardines, herring, cod liver oil, oysters, egg yolks, tuna, and salmon is very, very limited so I would need a supplemental source of Vitamin D, as I learned two years ago. My youthful sunshine exposure probably helped my calcium and vitamin D levels, but overexposure has resulted in me having numerous skin cancers.
Why do we need Vitamin D anyway? What purpose does it serve to our bodies? It’s main functions are as follows:
1. It aids in the body’s absorption of calcium and helps build strong bones
2. It blocks the release of parathyroid hormone (PTH) which reabsorbs bone tissue and
makes bones thin, brittle, and subject to fracture.
3. It plays a role in muscle function and prevents muscle weakness
4. It reduces the risk of falling in elderly patients
5. It helps prevent infections by positively affecting the immune system
What happens if we don’t get enough Vitamin D? Why is it important? Without Vitamin D intake and production people are prone to the following:
1. Bone pain
2. Muscle weakness
3. Rickets—a childhood bone disease that stunts bone growth
4. Osteomalacia—adult softening of the bone
5. Osteoporosis—adult reabsorption of bone calcium leading to fractures
6. General ill health—susceptibility to infection
7. Fatigue, tiredness
8. Depression
9. Hair loss
10. Impaired wound healing
Postmenopausal women are at high risk of osteoporosis due to a deficit of ovarian estrogen, calcium, and Vitamin D. This scenario is probably the most common reason Vitamin D supplements are prescribed.
Vitamin D can be deficient for a number of other reasons, many of which are quite common. They are categorized in the following ways:
1. Diseases that cause Vitamin D deficiency—kidney and liver disease, cystic fibrosis,
Crohn’s disease, Celiac Disease, Gastric bypass surgery, obesity
2. Drugs that cause Vitamin D deficiency—laxatives, corticosteroids, Cholesterol-lowering
drugs (Colestid, Questran), phenobarbital, Orlistat (appetite suppressant), Rifampin (TB
drug)
3. Misc. causes of Vitamin D deficiency—age (thin skin), immobility, darkly pigmented skin,
human breast milk, infant formulas
Vitamin D comes in two forms. They are:
D2–ergocalciferol, found in plant foods
D3–cholecalciferol, found in animal foods
Both forms of Vitamin D are used to raise low blood levels, but D3 is “twice as effective at raising blood levels as D2.”
Vitamin D is manufactured as a solution, capsules, and tablets. Dosage strengths are as follow:
Solution: 8000 IU (International units)/ml
Capsules: 50,000 IU
Tablets: 400 IU, 1000 IU, 2000 IU each
Supplemental Vitamin D is indicated for the treatment of low blood levels, and the dosage is age determinate. Routine screening, however, is not recommended. But if the patient is symptomatic, has osteoporosis determined by bone densitometry, or has one of the many risk factors or contributors, measurement is indicated. Dosages are based on age and the dosage range is determined by the blood level. What follows is a list of age ranges and the dosage range recommended for each:
Age 0-6 months—400-1000 IU/day
Age 6-12 months—400-1500 IU/day
Age 1-3 years—600-2500 IU/day
Age 4-8 years—600-3000 IU/day
Age 9-70 years—600-4000 IU/day
Over age 70 years—800-4000 IU/day
For osteoporosis the average recommended dose is 800-1000 IU/day
A lot of controversy surrounds Vitamin D. As mentioned at the beginning of this blog, many Vitamin D proponents have made all sorts of assertions about the benefits of supplementation. Clinical research has suggested that Vitamin D “might help prevent colon, prostate, and breast cancers,” and “might help prevent diabetes, heart disease, high blood pressure, and multiple sclerosis.” However, these conclusions are preliminary and open for debate. In the past ten years, however, many investigations have been done, and these assertions have not been verified. There has been no major breakthrough or epiphanous moment that changed the approach to the use or clinical significance of Vitamin D. Long-term studies have yet to conclude that Vitamin D should be recommended as an essential element of the daily health regimens of the general population.
Dr. G’s Opinion: Vitamin D is an essential element in calcium absorption and bone health. It has well-defined health benefits and is in common use by millions of patients. But it’s value as a major preventer of disease has not come to fruition. Ten years ago, people were saying Vitamin D was the next big thing in medicine; that it may be the answer to good health. But time has not shown that to be true.
References: google.com/search/Vitamin-d
