Doc told me to take one 2000 vitamin D per day. He stressed “don’t take 2”

I too take 2000. There is also vitamin D in the calcium I take. So far, so good on that.

Some information for you on "Can someone with MM have too much Vitamin D?"
Why, yes you can. Glad you asked!

Yes, too much Vitamin D is possible. Because it is a fat-soluble vitamin and just sits in your fat cells building up, as you will see below. It is not like Vitamin C for example which is a water-soluble vitamin and tends to flush the excess out of your system.

Although we need this essential vitamin to be healthy, vitamin D toxicity may occur if we consume very high doses of vitamin D supplements. Extra vitamin D is stored in fat cells, so it can build up over time and reach toxic levels. Although vitamin D toxicity is rare, it can cause severe organ damage, so it's important to recognize the symptoms

From: Medline
Hypervitaminosis D

Hypervitaminosis D is a condition that occurs after taking very high doses of vitamin D.

Causes
The cause is excess intake of vitamin D. The doses need to be very high, far above what most health care providers normally prescribe.

There has been a lot of confusion about vitamin D supplementation. The recommended daily allowance (RDA) for vitamin D is between 400 and 800 IU/day, according to age and pregnancy status. Higher doses may be needed for some people, such as those with vitamin D deficiency, hypoparathyroidism, and other conditions. However, most people do not need more than 2,000 IU of vitamin D a day.

For most people, vitamin D toxicity only occurs with vitamin D doses above 10,000 IU per day.

Symptoms
An excess of vitamin D can cause an abnormally high level of calcium in the blood (hypercalcemia). This can severely damage the kidneys, soft tissues, and bones over time.

The symptoms include:

Constipation
Decreased appetite (anorexia)
Dehydration
Fatigue and confusion
Frequent urination
Irritability
Muscle weakness
Vomiting
Excessive thirst (polydipsia)
High blood pressure
Passing large amounts of urine (polyuria)
Exams and Tests
Your provider will examine you and ask about your symptoms.

Tests that may be ordered include:

Calcium level in the blood
Calcium level in the urine
25-hydroxy vitamin D level
1,25-dihydroxy vitamin D level
Serum phosphorus level
X-ray of the bone
Treatment
Your provider will likely tell you to stop taking vitamin D. In severe cases, other treatment may be needed.

Outlook (Prognosis)
Recovery is expected, but permanent kidney damage can occur.

Possible Complications
Health problems that can result from taking too much vitamin D over a long time include:

Dehydration
Hypercalcemia
Kidney damage
Kidney stones

Can someone with MM have too much vitamin D?