Many of the vitamins and minerals are directly important to one’s thyroid health. For example, minerals such as iodine and selenium play important roles in the formation of thyroid hormone, and other minerals and vitamins have both direct and indirect effects on the thyroid gland. In addition to being important to one’s thyroid health, these vitamins and minerals have other vital roles.
These days it is almost impossible to get all of the essential vitamins and minerals through the food you eat. That’s not a problem though, as there are always vitamins and minerals to take, right? Without question, vitamins and minerals can help greatly, and I do recommend for everyone to at least take a multivitamin and multimineral, along with an essential fatty acid supplement. However, even this usually isn’t enough to prevent vitamin and mineral deficiencies from occurring. And it almost always isn’t sufficient to correct an existing deficiency.
Many decades ago, the Recommended Daily Allowance (RDA) was created by the United States government, as they were supposed to be nutritional guidelines for us to follow. These essentially were estimates of the nutrients most people required in order to prevent nutritional deficiencies from developing. However, over the years it has become clear that these guidelines aren’t completely accurate. In fact, many people who meet the RDA requirements still have moderate to severe nutritional deficiencies. So while it’s important to obtain a sufficient amount of vitamins and minerals from diet and nutritional supplements, most people need to get more than what the RDA suggests.
How Was The RDA Created?
To be fair, the RDA wasn’t just created randomly, as each vitamin and mineral was specifically looked at, and then recommendations were made based on age, gender, and numerous other factors. Every now and then this was updated, and in the 1990s the RDA was replaced with the RDI (Reference Daily Intake), although for the most part the values are the same.
In addition to not being sufficient to maintain one’s health or correct any existing deficiencies, following the RDI usually won’t prevent any diseases from developing. This includes cancer, heart disease, and of course thyroid and autoimmune thyroid conditions. While numerous factors can lead to a development of these conditions, one’s diet perhaps plays the biggest role. What’s sad is that many children have nutritional deficiencies, and many acquire these deficiencies during birth. After all, while a prenatal vitamin is great to take while pregnant, this usually won’t correct any existing mineral or vitamin deficiencies. As a result, if a pregnant woman has certain vitamin or mineral deficiencies, this very well may be passed down to the baby.
Yet, when I make a recommendation to one of my patients about supplements, it’s not uncommon for someone to look at the bottle and question why the dosage I’m recommending is well above the RDI. For example, selenium has a lot of important functions, as it is important for immunity, eye health, and also is important for the conversion of T4 to T3. The RDI for selenium is 70 mcg. Many people I consult with have a selenium deficiency. Because of this it is not uncommon for people to need to take much higher dosages of selenium than the RDI. Part of this depends on the form of selenium they are taking. For example, if they are taking selenium as part of a whole food supplement, then the dosage might not need to be as high due to the other nutrients and coenzymes present. On the other hand, if they are just taking a “typical” selenium supplement then they might have to take 400 mcg of selenium, or even a higher dosage than this, depending on the severity of the deficiency. Of course the same concept applies to other vitamins and minerals as well.
How Can One Determine The Appropriate Dosage?
Okay then, if the RDI isn’t accurate, then how can someone determine the exact dosage someone needs of a specific vitamin or mineral? First of all, it is just about impossible to know EXACTLY how much of a vitamin or mineral someone needs. For example, if someone has a magnesium deficiency, you might see one healthcare professional recommend 600 mg of magnesium, while another recommends 800 mg of magnesium. But you probably won’t see someone recommend 532 mg of magnesium. Besides it being easier to recommend such a dosage in 100 mg increments, it is extremely difficult to know exactly how much someone needs to take. Obviously the same concept can be applied to the RDI, as even if this was somewhat accurate, one needs to keep in mind that different people will require different dosages.
So when someone has a deficiency in a specific vitamin or mineral, one of course should see how deficient that person is. One also should factor in the person’s age and weight. It also is probably a good idea to obtain a food diary of that person to see what types of foods they are eating. Even though you usually can’t get all of the vitamins and minerals from one’s diet, the food people eat still needs to be factored in. But even after considering all of these factors, it still is somewhat of a guessing game, which is why retesting is important. For example, while vitamin D is something that should be obtained through the sun, many people have such low levels that supplementation becomes necessary. So if someone gets a blood test for 25 hydroxy vitamin D and has extremely low levels, I will put them on a large dosage of vitamin D3, and then after a few months of supplementing I will want to retest them to make sure the levels have improved and are within the desired range.
Are There Risks Of Overdosing?
The nice thing about the RDI is that one usually doesn’t have to worry about overdosing. While they might have nutritional deficiencies over time that lead to conditions such as cancer, heart disease, Graves’ Disease, or Hashimoto’s Thyroiditis, the good news is that those who follow the RDI guidelines won’t have to worry about dying due to vitamin A toxicity. All kidding aside, one does need to be careful not to overdose. However, it is difficult for this to happen, even when someone self-treats their condition. And it’s even more unlikely to happen when under the guidance of a competent healthcare professional. This doesn’t mean that you shouldn’t be careful about the dosages, as even though it is difficult to overdose when taking vitamins and minerals, it does happen from time to time. Once again, this is why testing and retesting is important, as if someone takes large dosages of the fat soluble vitamins (vitamin A, E, D, etc.) without retesting then there is a chance of overdosing. This can also happen when taking high dosages of the minerals, such as manganese and selenium. But if one goes about this cautiously then the risks of overdosing is minimal, and of course there are some great health benefits of supplementing with levels greater than the RDI.
In summary, if someone wants to achieve optimal health, then it’s probably best not to follow the guidelines of the RDI. This is especially true when trying to address vitamin and mineral deficiencies, as higher dosages are almost always required to correct these. For those who are concerned about overdosing, this is rare, but it does happen, and is why you want to test initially to see what the levels are, and then retest every now and then.