Vitamin ReviewsVitamin DPrescription D failed, switched to Peak Performance D - levels normalized in 6 months!

Prescription D failed, switched to Peak Performance D - levels normalized in 6 months!

2025-07-16 Vitamin Reviews Categroy:Vitamin D Views:36


Lab tests confirmed Peak Performance Vitamin D resolved chronic deficiency after prescription supplements failed; stabilized levels for bone health and calcium absorption.


This review is from Amazon.com for product:


Peak Performance Advanced Vitamin D 5000 IU with All 3 Types of Vitamin K Vitamin D3 and Vitamin K2, K1, MK-7 (MK7), MK4 Supplement. 60 Small and Easy to Swallow Vegetable Pills (5000 IU)


Peak Performance Vitamin D Solved My Deficiency – Lab Verified Results


I had my Vit-d tested at the Dr's and was told my level was very low, so Dr prescribed Vit-d supplement. I got it from my pharmacy (prescription strength) (not over counter) and took it for 6-7 months. when I went back to the Dr. I had them retest my Vit-d and was surprised to find it was still very low. Hardly any change in the level. So I got on Amazon and researched and decided on this one by Peak Performance, took it for 5-6 months then went back to Dr and had it retested.(and yes I had to pay for the retesting on my own) Was happy to find my levels were now in the normal range. I have been taking this now for about 2 years and each year my Vit-d level is normal. I ride horses and the last thing I want is brittle bones. You can take all the calcium you want but you need good levels of Vit-d to help absorb the calcium. I highly recommend this company.


Vitamin Basics & Tips


Vitamin D plays a critical role in calcium absorption and bone health, as highlighted in this review. Unlike many nutrients, vitamin D can be synthesized by the skin through sunlight exposure, but factors like geographic location, skin tone, and sunscreen use often limit natural production. Deficiency is linked to osteoporosis, muscle weakness, and immune dysfunction. While fatty fish and fortified foods provide small amounts, supplements are frequently necessary to meet daily requirements (600-800 IU for most adults).


Testing vitamin D levels via a 25-hydroxyvitamin D blood test is crucial, as symptoms of deficiency can be subtle. Optimal levels range between 30-50 ng/mL. Prescription-strength doses (50,000 IU/week) are sometimes prescribed for severe deficiencies, but absorption issues—as seen in this review—may require alternative formulations. Over-the-counter supplements often combine vitamin D3 (more bioavailable than D2) with fats like olive oil to enhance absorption, mimicking natural dietary sources.


Long-term maintenance requires consistency, as vitamin D is fat-soluble and stored in tissues. Pairing supplements with calcium-rich foods maximizes bone protection, though excessive intake (>4,000 IU/day) can cause toxicity. Regular monitoring ensures safety and efficacy, particularly for individuals with malabsorption conditions or limited sun exposure.



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Tags: vitamin d deficiency calcium absorption supplement effectiveness lab testing bone health


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