Thank you for your patience.
The endocrinologist would be recommended. They are the specialist that are best at checking thyroid, and should check for vitamin D as well, but you can also ask for it to make sure.
I think sometimes that doctors and other health care providers (don't want to just single doctors out!) don't listen too well, and this can be for several reasons... it may be that they are rushed. Or, it may be that their main focus is on the particular area of their specialty and they disregard issues outside of that. There has been great strides in the amount of medical knowledge available, and with this comes some fragmentation, since in order to learn it well, a specialist must focus on a particular area of medicine. For example, the psychiatrist might focus on one aspect, the nephrologist another, the endocrinologist another, and on and on. An underlying problem may never get addressed, instead only various symptoms are treated.
At the same time, sometimes people/patients may not be ready to hear certain things. A very candid physician/health care provider may find themselves being taken as rude or lacking in etiquette, and certainly when talking about something as personal as one's health, people can be easily offended, may feel guilt or feel like they are being blamed, even when they are not. So certain subjects are not even brought up because of the 'can of worms' that it may open.
I'm glad you asked about going 'the natural remedy route'. I do believe it is to the patient's advantage to take the best from what modern medicine has to offer and the best from what alternative (or a better term is 'complementary') medicine has to offer.
One still has to be picky with complementary medicine, and know what is legitimate and what is a money making scam.
In general, besides certain herbal products that have been shown through research to be beneficial for certain conditions, much of complementary medicine is basic age old wisdom.
Consider, that the illnesses that are present today are not the illnesses that people had before the 1950's.. In the past, people died of viruses and bacterial infection, or from the effects of trauma and inadequate technology. About the same time antibiotics and technological advances took care of these major health issues, we also advanced in that we could preserve food for long times, resulting in convenience and packaged foods, and machines did the harvesting and took care of our transportation. So, while technological advances solved one area of medicine, it caused most of our modern health problems.
The health issues that effect us now: high blood pressure and other cardiovascular disease, sleep apnea, endocrine imbalances, depression, were not present in the past (except among the very wealthy - that could afford to pay other people to do their work, and to eat what ever they liked).
So, what this shows us, is that we can solve these illnesses, and we do this by living in a much simpler manner. It may not seem simpler at first, because we have to change some habits that we are used to, and change is always difficult, at least psychologically, in the beginning.
One has to eat more simple, less processed foods, and instead of having machines drive us about, we need to start walking or biking to get our errands done. If this is not possible in your area, then you do the best you can... you start step by step. Adding walking, learning new ways to prepare foods, and being open to taking a few new steps a day..
The issue for you, will be, is your husband willing to be open to living his life in a new way?
I have found this website to be very helpful in learning to live in healthier ways. It is a non-profit website and addresses mental health, but also nutritional, and physical requirements for health.
This section is the diet and nutrition and it gives very practical advice:
This is the main page, and if you look to the left, you will find directions on proper sleep, work and career; brain, body and spirit; caregiving (as I mentioned in the first post) and more. http://helpguide.org/
So basically, I am recommending that he does go to the endocrinologist and follow the recommendations. At the same time, he can treat the underlying problems through natural health methods - this means increase in activity, healthier diet, sleep regulation (don't forget daily exposure to sunlight). These things have been shown in actual studies to reduce blood pressure, sleep apnea, and depression, among other issues. Again if he does these things, I can guarantee he will improve over all. He just has to get through any psychological hurdles and take those first steps. Additionally, you may want to consider seeing a Naturalpathic physician as they can give you a personal program and direction on diet, activity, and more, (or consider seeing a regular nutritionist.)
Please feel free to reply with any questions or concerns, i am happy to discuss anything until you are satisfied with your answer (and beyond)