Vitamin D is, indeed, a necessary nutrient. But how much vitamin D does each of us require in a day? According to the Institute of Medicine’s Food and Nutrition Board’s old 1997 recommendations, 2,000 IU of vitamin D per day is safe for adults and 1,000 IU per day is safe for infants up to 12 months of age.
Sources of Vitamin D:
The majority of this can be obtained from foods such as oily fish (salmon, sardines, herring, and mackerel), red meat, liver, egg yolks, and in some countries such as the United States and the United Kingdom, where foods such as some fat spreads and breakfast cereals are fortified.
Following a healthy diet, exposure and doing some of your walking and working in sunlight/sunlight is beneficial to the body’s synthesis of calcium and phosphates, which are required to keep bones, teeth, and muscles healthy.
Toxic effects of vitamin D:
However, too much of a good thing is a bad thing. Too much vitamin D can result in an abnormally high blood calcium level, which can cause nausea, constipation, confusion, an irregular heart rhythm, and even kidney stones.
Unless you overdose on cod liver oil, food sources cannot cause vitamin D toxicity, and supplements account for nearly all vitamin D overdoses. What kind of harm can Vitamin D toxicity cause? It causes a calcium buildup in your blood (hypercalcemia). The patient experiences nausea and vomiting, as well as weakness and frequent urination. If not treated in a timely manner, this excess Vitamin D in the blood can lead to bone pain and kidney problems, such as the formation of calcium stones.
Vitamin D is almost considered a ‘Magic Pill’:
But take a look around you. Because vitamin D is being marketed as a cure-all for most ailments and a preventive measure for a variety of health problems, most people believe that taking vitamin D supplements is beneficial to their health; that it will help prevent cancer and dementia, as well as infections and heart disease.
According to Dr. Robert H Shmerling, a former clinical chief of the division of rheumatology at Beth Israel Deaconess Medical Center (BIDMC) and a current member of the corresponding faculty in medicine at Harvard Medical School, many of the supposed benefits of vitamin D supplements remain unproven.
Dr. Shmerling warns that, while none of these vitamin D claims have been proven, millions of people take it on a regular basis, believing it will help prevent a variety of illnesses, including certain autoimmune conditions.
Is that correct? Is Vitamin D our antidote to autoimmune diseases?
Dr. Shmerling cites a new randomised, controlled study published in the BMJ that investigates this question in depth. Although the cause of the majority of known autoimmune diseases is unknown, the leading theory is that the body’s immune system is misregulated. Normally, the immune system defends the body against invaders such as infections and aids in the repair of damaged tissues. When an autoimmune disorder develops, the immune system attacks the host. Immune cells, for example, attack joints, lungs, and other parts of the body in rheumatoid arthritis.
Yes, vitamin D “talks” to the immune system:
studies have shown that vitamin D can interact with immune cells, affect genes that regulate inflammation, and alter immune response. So it makes sense to look into whether taking vitamin D supplements can help treat or prevent autoimmune disease.
The BMJ study drew on data from a large trial that was published several years ago.
Over 25,000 elderly people were randomly assigned to one of two tests:
Every day, take 2,000 IU of vitamin D or an identical placebo dose (inactive pill). (This is more than the recommended daily allowance for adults, but less than the upper limit of 4,000 IU.)Alternatively, a daily dose of 1,000 mg omega-3 oil or an identical placebo.
New autoimmune disease diagnoses among study participants were tallied after an average of five years.
What did the new study discover?
According to Dr. Shmerling, the findings were overly interpreted. Yes, researchers discovered that adults who took vitamin D supplements were less likely to develop autoimmune disease. However, Dr. Shmerling believes that some publications went too far with their conclusions and headlines. He highlights a few headlines that read:
- Vitamin D supplements do, in fact, lower the risk of autoimmune disease (New Scientist)
- According to a new study, taking vitamin D on a daily basis can help prevent this disease (Eat This, Not That!)
- According to one study, taking vitamin D and omega-3 fish oil supplements on a daily basis reduces your risk of developing arthritis by 22%. (Daily Mail)
Dr. Shmerling believes that, while all of the headlines make it sound like a miraculous cure, a closer examination of the study reveals a different storey.
When examined closely, the study appears to have flaws and shortcomings:
- Vitamin D supplementation did not reliably prevent any single autoimmune disease.
- Researchers saw a benefit only when the numbers of all the autoimmune diseases were combined.
- When only the last three years of the study were examined, the benefit of vitamin D became clearer. This implies that it takes time to reap the benefits of a daily supplement.
- This randomised controlled trial is one of the best to investigate the effect of vitamin D supplementation on the risk of developing autoimmune disease.
- Nonetheless, the study relied on self-reported cases, which were later confirmed by a review of medical records. As a result, it’s possible that some cases of autoimmune disease went unnoticed.
According to Dr. Shmerling, the majority of common autoimmune diseases, such as lupus and rheumatoid arthritis, begin in early adulthood. If the study had included younger participants, the results might have been different.
Do we all need to take vitamin D supplements?
According to Dr. Shmerling, based on the findings of this study, “No, I’d say. For starters, these findings must be validated by other independent researchers. Moreover, despite exaggerated headlines, the actual risk reduction was only 2.5 cases out of 1,000. To prevent a single case of autoimmune disease, hundreds of people would need to take vitamin D daily for years. Vitamin D can interact with other medications, and taking too much of it can be harmful.”
Bottom Line:
Is vitamin D a safe, all-natural wonder drug capable of preventing or treating a wide range of diseases? According to Dr. Shmerling, it is best to keep an open mind. Supplemental vitamin D may be especially beneficial for people with a family history of certain autoimmune diseases. Meanwhile, we recommend that you eat the right foods, stay active, and get a safe and significant amount of sun on your skin, and that you consult your doctor before following any well-meaning health-related advice given by anyone else, whether here or elsewhere.
